Ten plates (XXIII, XXIV, XXV, XXVI, XXVII, XXVIII, XXIX, XXX, XXXI and XXXII), on the scale of 6 miles to an inch, covering consecutive areas as indicated on Pl. XXII, display the definite geographic location of the shores; and all their more remarkable portions are described, with statement of the sections or often the quarter-sections under consideration, in the text. The arrangement of the sections in each township is shown in fig. 1, on page 11.
Many of the farmers whose houses are built on or near to the old beaches have decided to their own satisfaction, as I learned by conversation with them during the progress of these surveys and levelings, that these beach ridges of gravel and sand are the same as those of now existing lakes of large size, and that consequently the flat Red River Valley so bounded was once the bed of a great lake. These residents will be enabled, by the following descriptions and maps to trace the continuity of the shores seen near their own homes to distances of many miles away and, indeed, around all the prairie portion of the ancient lake.
With the progress of agriculture, which is rapidly bringing all this lake bed into cultivation, certain features of the deserted shores that were very distinct at the time of my examination will doubtless be obscured or obliterated. Many of the groves here noticed as occurring along stream courses [p.277] or elsewhere in the neighborhood of the old shore-lines will probably cease to exist within a century, or in some cases within a score of years. On the other hand, many artificial groves surrounding farmhouses, and lines of trees cultivated on the divisions of property or of adjacent fields, will probably more than replace such loss, making the country more beautiful and less liable to be swept heavily by winds. But the extensive views enjoyed by the writer and his assistant rodman as they advanced along the course of the beaches, mapping them and determining their elevation, will be then hindered by the cultivated groves, tree rows, and hedges. Only upon a prairie country, such as this was when its shore-lines were first traced, can the grandeur of the proofs of existence of glacial lakes, held by the obstruction of the departing ice, be taken in by an unimpeded vision of the smooth lake bottom on one side stretching out to a distance of 10 or 20 miles within sight, of the bordering beach, running as one unbroken ridge of gravel and sand in a nearly direct course discernible for several miles, and of the broad, slightly higher expanse of more undulating and knolly glacial drift outside the lake area.
From these descriptions of the beach ridges and eroded shores of the old lake, its levels at the time of formation of these shore-lines are deducible approximately. The elevations of the crests of the beach ridges, as recorded in these notes, are commonly 5 to 10 feet, or rarely 15 feet or more, above the level held by the lake when the beaches were heaped up by the waves, chiefly during storms. Where the descents of the slopes of these gravel and sand ridges are noted, the lake level was nearly always below the depression which borders the landward side of the beach and was near the foot of the lakeward slope. Cliffs eroded by the lake waves give more definitely the plane of the water surface which cut into the base of the eroded escarpment, usually consisting of till, undermining it and carrying away its material to form a very gently descending slope, which was covered by the margin of the lake.
Fluctuations of the lake level, which doubtless rose in summer a few feet higher than in winter, because of the variations in the volume of water supplied from the melting ice-sheet, have given a variability within limits generally 5 feet and perhaps sometimes 8 or 10 feet apart to the heights of [p.278] the lake and of its shore deposits and planes of erosion in each of the more than thirty stages which these shore-lines exhibit. The high-water surface of the summers, however, had probably a nearly uniform elevation during many years in each stage, producing therefore a beach or eroded line of nearly constant height. On the other hand, the reduced lake level of the winters, when the superficial melting of the ice-sheet ceased and the lake doubtless became mostly frozen over, was likewise at nearly the same elevation from year to year; but the beach ridges formed by the strong wave action of the autumn, winter, and spring storms, with the effects of the drifting lake ice during the breaking up in spring, would be mostly washed away by the ensuing high water of the summer, when the glacial melting attained its maximum. As the result of these annual oscillations of the lake surface, gravel and sand from the material eroded during the storms of winter, both from bordering cliffs and from the shallow lake bed close along the shore, have been chiefly preserved in beach deposits at the higher plane of the fluctuation reached in summer.
Periodic oscillations occupying several years between successive maxima of the lake level were also probably caused by cycles of increase and diminution in temperature and rainfall, with consequent irregularity in the yearly amount of the glacial melting. The cycles of rise and fall of the great Laurentian lakes have a somewhat uniform average length of ten to twelve years, as stated in Chapter XI, the maximum heights of these lakes being 5 to 6 feet above their lowest recorded stages. But, on account of the great variation of the tribute received by Lake Agassiz from the departing ice-sheet in the alternating warm and cold portions of each year, probably its annual fluctuations of level equaled or exceeded the changes of longer periods in the Laurentian lakes, which receive a somewhat steady supply through all the seasons, but are raised by excess of rainfall during a few years together and then lowered by a series of drier years.
Our description of the highest shore-lines of Lake Agassiz may well begin at the mouth of this lake, the present site of the northern end of Lake Traverse. Thence the uppermost or Herman beach was traced [p.279] eastward and northeastward through Traverse County and the most northwestern township of Stevens County, Minn., to Herman, in Grant County, nearly 20 miles east of Lake Traverse. From this place the Herman beach runs nearly due north 132 miles to the north side of Maple Lake, in Polk County, about 20 miles east-southeast of Crookston. Beyond Maple Lake the course of this shore-line is known to be nearly east to the south side of Red and Rainy lakes; but it passes through a wooded and uninhabited country where it is impracticable to trace its course exactly and determine its height by leveling.
Along the distance of about 160 miles, as measured by long, straight lines, or about 175 miles, following the larger bends of the shore-line, from Lake Traverse to Herman and Maple Lake, the boundary of Lake Agassiz lies in a prairie region, mostly having a very smooth and regular surface, which could not be surpassed in its adaptability for receiving and preserving a record of the old lake level. The Herman beach lines, single on the southern part of the lake border, but double and even quadruple in Clay County and northward, have been carefully mapped across this expanse of prairie, and their heights have been determined by leveling. The principal features of this series of beaches are described in the following pages.
Especial description is also given of the two chief delta deposits of this part of the old lake border. These were brought into the lake, contemporaneously with the formation of the Herman beach, by the glacial representatives of the Buffalo and Sand Hill rivers. They cover small areas, in comparison with the Sheyenne, Elk Valley, Pembina, and Assiniboine deltas on the west margin of this glacial lake.
(PLATE XXIII.)
Within the first 4 miles eastward from the northeast end of Lake Traverse the Herman shore of Lake Agassiz is an eroded bluff of till, rising from the south side of the Mustinka River to a height of 75 to 100 feet above the river and lake. The altitude of Lake Traverse at its lowest and highest stages is 970 and 976 feet above mean tide sea-level. When the lake falls below 973 or 972 feet, which occurs during the [p.280] dry season nearly every summer, it ceases to outflow by the Bois des Sioux, and that stream becomes reduced to a series of stagnant pools. The eroded bluff noted, and others of the same character lying on each side of the Bois des Sioux at a distance of 3 to 4 miles apart between Lake Traverse and White Rock, were finished by the outflow of the glacial River Warren, but probably their erosion was begun by a stream outflowing here from the Red River Valley during the Aftonian interglacial stage between the Kansan and Iowan stages of ice accumulation and extension.(1)
After following the old lake shore eastward to a distance of about 4 miles from Lake Traverse, the steep bluff gives place, in sections 2 and 11, Walls, to a gentle slope of the surface, which allowed the accumulation of a distinct beach ridge of gravel. This is smoothly rounded, 15 to 20 rods in width, bounded eastward on the side toward the ancient lake by a moderately steep slope which descends 10 or 12 feet, the land 1 to 4 miles distant northeastward within the area that was covered by the lake being 20 to 40 feet below this beach. On the other side this ridge is succeeded by a slight depression 2 to 5 feet deep, beyond which the land soon rises 10 to 15 feet above the beach. The material of the beach is gravel, containing pebbles up to 2 or 3 inches in diameter, but all the surface elsewhere on each side is till. The crest of the beach here is 1,060 to 1,062 feet above the sea.
The beach next passes southeastward through sections 30 and 32, Croke, having in places a maximum altitude of 1,067 feet, being piled several feet above its average height.
Between 2 and 3 miles farther southeast, near the middle of section 9, Tara, the beach ridge sinks to the height of 1,057 feet. Its contour and material, and those of the adjoining areas, are nearly the same as at the locality first described. The width of the gravel beach here is 25 or 30 rods; the smoothed surface of till which descends thence northward is 10 to 20 feet lower in its first mile; on the south the sheet of till is at first for 40 or 50 rods about 5 feet lower than the top of the beach, but beyond this it [p.281] gradually rises to a height 10 to 25 and 50 feet above the beach. The average height of its moderately undulating surface 6 miles to the south, at Graceville, is nearly represented by the railroad at the depot there, 1,109 feet. Farther to the east, through this township, the crest of the beach ranges from 1,057 to 1,062 feet.
For the next 3 miles eastward, lying in the northwest part of Leonardsville, the beach is less conspicuous than usual, but in sections 8, 5, and 4 of this township the shore-line is again distinctly marked by a slight terrace in the till, descending northward in a moderately steep slope 5 to 10 feet, rather than by the usual accumulation of gravel. The top of this terrace is at 1,056 to 1,057 feet.
A few miles farther north, in the southeast part of section 24, Doleysmount, the beach is a low gravel ridge, 20 rods wide and 5 feet high above the adjoining surface, its crest being 1,060 to 1,061 feet above the sea.
These determinations indicate that in Traverse County the surface of Lake Agassiz during its maximum stage was very nearly 1,055 feet above our present sea-level.
In the northwest corner of Stevens County this upper or Herman beach is well displayed in the northwest quarter of section 19, Eldorado, having an elevation of about 1,063 feet. Through section 18 it is 20 to 25 rods wide, with its crest at 1,063 to 1,066 feet, being a gently rounded ridge of sand and gravel, containing pebbles up to 2 or 3 inches in diameter. Its height is 7 to 10 feet above the land next west and 5 feet above the depression next east. The surface on each side is till, slowly falling westward and rising eastward.
In the southeast part of section 7 in the same township the crest of the beach is at 1,067 to 1,070 feet. Here and onward the next 2 miles, through the northwest quarter of section 8, the southeast part of section 5, and the western and northern part of section 4, this formation is finely exhibited in a ridge of gravel and sand 20 to 30 rods wide, 15 feet or more above its base westward, where lay the glacial Lake Agassiz, and 8 to 10 feet above the depression eastward, which divides it from the higher, moderately undulating expanse of till beyond. In the east part of section 5 its elevation is 1,065 feet, and through section 4, 1,065 to 1,072 feet.
[p.282] This beach near the middle of section 15, Logan, Grant County, is about 30 rods wide, with a broad, nearly flat top, at 1,070 feet, having a descent of about 15 feet on its northwest side to the area of Lake Agassiz and half as much on the southeast, the surface thence rising very gradually in the 1½ miles eastward to Herman. The beach ridge is gravel, the land at each side till.
Elevations determined in this vicinity by the railway surveys are as follows: Track at Herman, 1,072 feet above the sea; crest of the beach about 1½ miles northwest of Herman where it is cut by the railway, and for 50 rods southwestward, 1,064 to 1,066 feet; depression, 40 rods wide, next southeast at the railroad (lowest 20 rods from the top of the beach), 1,060 to 1,063 feet; surface of till at the southeastern snow fences of the railroad, about a third of a mile southeast from the beach, 1,073 feet; at the northwest end of the northwestern snow fences, about 25 rods northwest from the highest part of the beach, 1,054 feet; and at the original one hundred and eightieth mile post, about a quarter of a mile northwest from the last, 1,049 feet.
Several farmhouses are built on the top of the Herman beach between 6 and 10 miles north of Herman. At Joseph Moses's house, in the northwest quarter of section 18, Delaware, the crest of the beach ridge has a height of 1,066 to 1,067 feet, and the piazza of the house is at 1,067 feet. H. D. Kendall's house, at the east side of the southeast quarter of section 12, Gorton, on the western slope of this beach, is at 1,062 feet; while the top of the beach ridge, about 25 rods east of Mr. Kendall's house, is at 1,067 feet.
Crest of the beach through the next 1½ miles, north from Mr. Moses's house, along the west side of sections 18 and 7, Delaware, 1,066 to 1,068 feet. The beach for this distance is finely exhibited, having a width of about 25 rods, rising 5 to 8 feet above the depression at its east side and 10 to 15 feet above the land west. L. I. Baker's house sill, in the southwest quarter of section 6, same township, of same height with the top of the beach ridge, on which it is built, 1,068 feet.
[p.283] Beach in section 31, Elbow Lake, not so conspicuous as usual, 1,066 feet; in the southwest quarter of section 18, same township, at the house of Henry Olson, a gracefully rounded low ridge, as elsewhere, composed of gravel and sand, including pebbles up to 3 inches in diameter, 1,065 to 1,066 feet; at Mrs. John S. Ireland's, in the northwest quarter of the same section 18, 1,070 feet; at Dr. J. M. Tucker's, in the northeast quarter of section 2, North Ottawa, 1,071 feet; about a mile north of the last, near the north side of section 35, Lawrence, 1,075 feet; and about a mile farther north, also 1,075 feet. Through nearly the whole of this distance it is a typical beach ridge of sand and gravel.
Crest of beach about 30 rods west of M. L. Adams's house, in the northeast quarter of section 26, Lawrence, 1,075 feet, being 4 feet above the land adjoining this ridge on the east and about 10 feet above the flat land near on the west; in section 23, same township, 1,076 feet; and near the south side of section 10, same township, 1,069 to 1,074 feet.
Extensive sloughs or marshes occur in section 36 and in sections 25 and 24, Lawrence, each being about a mile long, lying on the east side of the beach ridge at Dr. Tucker's and reaching 2½ miles northward; the elevation of these above sea-level is about 1,060 feet.
In the north part of section 10 and the south part of section 3, Lawrence, this shore-line of Lake Agassiz is not marked as usual by a gravel ridge, but by a somewhat abrupt ascent or terrace in the drift sheet of till, the elevation of the top of which, composed partly of gravel, is 1,085 to 1,079 feet; base of this terrace and land westward, consisting of till, slightly modified on the area of Lake Agassiz, 1,060 to 1,050 feet. This escarpment, the eroded shore-line of the lake, passes about 40 rods west of N. S. Denton's house, at the north side of section 10.
Beach in section 34, Western, the most southwest township of Ottertail County, near John F. Wentworth's, 1,070 to 1,075 feet; surface at Mr. Wentworth's barn, 1,072 feet. Beach 25 rods east of Albert Copeland's house, in the southwest quarter of section 28, Western, 1,070 to 1,066 feet; where it is crossed by the old road from Fergus Falls to Campbell, near the northwest corner of this section 28, 1,072 feet; through the next 2 miles north, finely developed, with nearly constant height, [p.284] 1,072 feet, being 7 to 10 feet above the depression at its east side and 20 feet above the area westward, which was covered by Lake Agassiz; at Michael J. Shortell's, section 9, same township, 1,073 feet; 1 mile farther north, 1,078 feet; and at A. J. Swift's, in the northwest quarter of section 4, 1,076 feet. The beach at Mr. Swift's and for half a mile farther north is well exhibited, and, as in many other places, is bordered on its east side by a narrow strip of marsh.
Beach in the northeast quarter of section 33, township 132, range 44, 1,076 feet; top of large aboriginal mound, situated on the beach here, 1,082 feet; land 30 rods west, 1,060 feet; lakelet 250 feet in diameter, about an eighth of a mile northeast from the large mound, 1,051 feet.
Red River of the North, near the northeast corner of section 33, township 132, range 44, 1,014 feet; on the line between this township and Buse, 1,041 feet; and at Dayton bridge, in the southwest quarter of section 20, Buse, 1,064 feet, being 8 feet below the bridge. S. A. Austin's house foundation in the southwest quarter of section 29, Buse, 1,147 feet. Old grade for railroad at Dayton bridge, about 1,102 feet.
No noticeable delta was brought into Lake Agassiz by the Red River.
Crest of beach near the south side of section 21, township 132, range 44, 1,077 feet; in this section 21, an eighth of a mile north of the road from Fergus Falls to Breckenridge, 1,079 feet; and for the next mile north, 1,077 to 1,080 feet. This is a typical beach ridge, gently rounded, composed of sand and gravel, containing pebbles up to 3 inches in diameter; its width is 30 to 40 rods, and its height above the very flat area on its west side, which was covered by Lake Agassiz (usually somewhat marshy next to the beach), is about 15 feet. On the east there is first a depression of 4 to 6 feet, succeeded within a fourth of a mile eastward by a gentle ascent, which rises 5 to 10 or 15 feet above the beach. The material on each side of the beach is till, slightly modified by the lake on the west. It is all fertile prairie, beautifully green, or in many places yellow or purple with flowers during July and August, the months in which this survey was [p.285] made. In August, 1881, no houses had been built on this beach, nor within 1 mile from it, along its first 11 miles north from the Red River, the first house found near the beach being in section 26, Akron, in Wilkin County.
Beach at a low portion, probably in the southeast quarter of section 5, township 132, range 44, 1,075 feet. A lake nearly a mile long lies on the flat lowland about 11 miles west from this low part of the beach. The elevation of this lake was estimated at 1,055 or 1,050 feet; it is only a few feet lower than the general surface around it. Beach, probably near the north side of this section 5, 1,078 feet. On its east side here and for a half mile both to the south and north is a slough, partly filled with good grass and partly with rushes; its width is about a quarter of a mile, and its elevation about 1,070 feet. The land west of the beach descends, within 1 or 2 miles, from 1,060 to 1,050 feet.
Beach at its lowest portion for this vicinity, about a half mile north of the preceding and near the center of section 32, Carlisle, 1,070 to 1,068 feet, being only 2 feet above the marsh or slough on its east side. A railroad grade, abandoned, lies a third of a mile east of this. Beach a fourth of a mile farther north, 1,077 feet, and, about 1 mile north from its lowest portion, 1,075 feet, cut by a ravine, the bottom of which is nearly at 1,063 feet. This ravine is some 30 rods west of the abandoned railroad embankment.
Railroad grade where it crosses the beach, about a mile northwesterly from the ravine, mentioned, 1,077 feet. Beach here, 1,076 feet, being 8 to 10 feet above the slough on its east side, and having about the same height above the marsh next to it westward. The material of the beach, shown by the railroad embankment, which is made of it along a distance of a third of a mile, is coarse gravel, with abundant pebbles of all sizes up to 6 inches in diameter, fully half of them being limestone.
Crest of beach in the south half of section 23, Akron, 1,079 to 1,080 feet; in the northwest quarter of this section 23, 1,075 to 1,080 feet. Through sections 14, 10, and 3, Akron, the beach does not have its ordinary ridged form, but is mostly marked by a deposit of gravel and sand lying upon a slope that rises gradually eastward. Its elevation here is [p.286] 1,075 to 1,085 feet. In the southern part of this distance, probably in the southwest quarter of section 14, the margin of the flat, somewhat marshy area that appears to have been covered by Lake Agassiz is very definite at 1,075 feet, which thus was probably the height of the lake here.
Beach in the southwest quarter of section 34, Tanberg, composed of gravel, nearly flat, 25 to 30 rods wide, 1,084 to 1,087 feet, bordered by a depression of 2 to 5 feet on the east and by an expanse 10 to 15 feet lower on the west. Beach in the northwest quarter of this section 34, also 1,084 to 1,087 feet. Here the land next east does not present the usual slight hollow dividing the beach ridge from the higher land eastward; instead is a springy belt, mostly 1,089 feet, quite marshy, yet slowly rising 2 to 4 feet above the belt of beach gravel. Occasional hummocks, about 2 feet above the general surface and covered with rank grass about 6 feet high, form part of this belt of marsh and shaking bog. Next to the east is a slough about 1,086 feet, or 3 feet below the springy tract, and this is succeeded by a surface of moderately undulating till, which rises gradually eastward.
Sloughs, mostly filled with rushes and having areas of water all the year, occupy a width of 1 to 2 miles next west of the shore-line and beach of Lake Agassiz and extend nearly continuously 10 miles from south to north, from the middle of Akron to the south edge of Prairie View Township. The elevation of this belt of sloughs is 1,080 to 1,050 feet, being considerably lower on its west than on its east border. The highest land westward in the west part of Tanberg, between these marshes and Manston, is about 1,060 feet. Along most of this distance the ordinary beach ridge is wanting.
Great Northern Railway track at Lawndale water tank, 1,089 feet. Here a side-track has been laid, extending about a third of a mile northward, with its northern end some 50 rods east of the main line, to take ballast from the beach, which is well exhibited here and onward, having its typical ridged form. The elevation of its crest is 1,091 to 1,094 feet. It is composed of gravel and sand in about equal amounts, interstratified mainly in level layers, but with these often obliquely laminated. Most of the gravel is quite fine, and the coarsest gravel found here has pebbles only 2 to 3 inches in diameter. About half of it is limestone.
[p.287] Beach ridge 1 mile farther north, 1,094 feet; three-fourths of a mile north of the last and close south of a ravine, 1,099 feet. Beach about 3 miles north from Lawndale water tank, probably in the south part of section 16, Prairie View, not ridged, but a belt 25 rods wide, of gravel and sand, on a slope of till that rises eastward, 1,080 to 1,102 feet. Beach, a ridge of gravel and sand, a third of a mile north from the last, 1,105 feet. The beach in section 9 of this township is spread more broadly than usual, its higher parts being 1,095 to 1,107 feet. Here the beach deposits are crossed obliquely by several broad depressions 10 to 15 feet deep, running south-southwest. The depression east of all these banks of gravel and sand is about 1,090 feet above the sea.
Entering Clay County, the elevation of this upper or Herman beach at the east side of section 33, Humboldt, is 1,100 feet above the sea. The land thence for two-thirds of a mile east is low and smooth, not higher than the beach. Beyond this the next third of a mile northeastward, in the north part of section 34, is very rocky, with many bowlders up to 6 and rarely 10 feet in diameter, the contour being moderately rolling 10 to 30 or 40 feet above the beach. Farther eastward here and through the next 15 miles north to the Northern Pacific Railroad, the moderately rolling or smoothly hilly till rises 100 to 250 feet above this beach within the distance of about 10 miles between it and the east line of the county.
Elevation of the crest of the beach ridge in the east half of section 28, Humboldt, one-fourth to three-fourths of a mile south of Willow River, 1,098 to 1,100 feet. In the 3 miles westward to Barnesville the area that was covered by Lake Agassiz shows here and there bowlders projecting 1 to 2 feet above the surface, which is till, slightly smoothed by the lake.
Great Northern Railway track at Barnesville, 1,020 feet.
The beach for three-fourths of a mile north from Willow River consists of a belt of gravel and sand, lying on an eastwardly ascending slope of till. Through the next 1½ miles northward, in the northwest quarter of section 22 and in section 15, Humboldt, the shore of Lake Agassiz is not marked by the usual beach of gravel and sand, but instead becomes a belt of marshy and springy land 20 to 50 rods wide, rising by a gentle slope eastward, rough with many hummocks and hollows, in some portions forming a quaking bog, in which horses and oxen attempting to cross are mired.
[p.288] In the next 2 miles northward, through sections 10 and 3, Humboldt, the beach is nowhere well marked as a ridge, but is mainly a belt of gravel and sand, lying on a slope of till, which gradually rises 30 or 40 feet higher at the east. The lack of typical beach deposits on this shore through the north half of this township is probably due to its sheltered situation in the lee of islands on the northwest. The course of the shore currents, determined by the prevailing winds, seems to have been southward, as on the shores of Lake Michigan.
Highest part of southern island in the east edge of Lake Agassiz, in the northeast quarter of section 5, Humboldt, extending northward into Skree, 1,117 to 1,122 feet. This island was about 1 mile long from south to north. Crest of beach on its west side, a well-developed ridge of gravel near the middle of the north line of section 5, 1,095 feet; and for a third of a mile north-northwest from this, 1,094 to 1,096 feet. On the east side of the beach, as it continues northward, is a slough two-thirds of a mile long from south to north and about 30 rods wide, 1,085 feet. This was evidently filled by a lagoon, sheltered on the southeast by the island and separated from the main lake by the beach. Toward the northeast it widened into a shallow expanse of water 8 to 15 feet deep, about 11 miles wide, divided from the broad lake on the west by two islands and this beach or bar which connected them. Lake Agassiz here appears to have stood at the height of 1,090 to 1,095 feet.
Top of the beach or bar in the north part of section 32, Skree, a broad rounded ridge of gravel, with pebbles up to 3 or 4 inches in diameter, 1,103 feet, and through the next half mile, in the south half of section 29, 1,102 to 1,104 feet. Along part of this distance the beach ridge is bounded eastward by a steeper descent than usual, the land next east being 1,085 to 1,090 feet above the sea. This beach or bar continues northward in a typical ridge through sections 29 and 20, same township.
Beach or bar at L. Williams's house, in the southeast quarter of section 20, Skree, 1,101 feet; a quarter of a mile farther north, 1,106 feet; three-quarters of a mile north of Mr. Williams's, near the middle of the north line of section 20, 1,110 feet, continuing a very definite ridge through the south half of section 17, 1,109 to 1,110 feet.
[p.289] Near the middle of this section 17 the beach deposit of gravel and sand ceases at the west side of the northern island, which was situated in the east half of this section and extended also eastward in a long, low projection nearly across the south side of section 16, and northward half way across section 8. Highest part of this island, in or near the northeast quarter of the northwest quarter of section 17, about 1,125 feet. The old shore of the north half of this island has no beach ridge nor other deposits of gravel and sand, but is plentifully strewn with large bowlders up to 5 and 10 feet in diameter, and many of these project 2 to 5 feet above the general surface. The lake waves eroded here, and deposited the sand and gravel gathered from this till as a beach a little farther south.
North and northeast from this northern island a lower expanse, nearly level and in some portions marshy, resembling the broad, flat valley of the Red River, extends 1½ miles to the east shore of Lake Agassiz, its height being 1,075 to 1,090 feet, or 10 to 25 feet below the surface of the ancient lake. The distance between these islands was 2 miles, and the distance, from the summit of the first to that of the second, nearly due north, 4 miles. Each of them rose about 25 feet above Lake Agassiz. The strait between them and the mainland eastward was 10 to 20 feet deep and from 1 to 1½ miles wide, excepting a narrow place near the southeast corner of section 16. East of the northern island the main shore of the lake was indented by a bay a third to a half of a mile wide and about 10 feet deep, stretching 2½ miles southeastward from the lakelet at the northwest corner of section 10 to the west part of section 23, Skree. The shore of the lake east of its islands along this bay and northwesterly to the north line of this township lacks the beach deposits which elsewhere distinguish it.
In its continuation northwestward the shore-line of the old lake runs diagonally across section 32, Hawley, where it again presents the anomalous character of a very springy and marshy belt, 20 to 40 rods wide, rough with hummocks and in many places so deeply miry that it is dangerous for teams. This boggy tract has a gentle descent westward, its lower portion being about 1,085 feet, and its upper border, very nearly level across this entire section, being 1,098 to 1,100 feet, which was almost exactly the height of Lake Agassiz, as shown by its distinct beach of gravel and sand at the [p.290] south and north. Next eastward rises a moderately undulating slope of till, strewn with abundant bowlders; and rarely a bowlder 2 to 5 feet in diameter is seen on the springy land that marks the border of the ancient lake.
(PLATE XXV.)
The delta brought into the east side of Lake Agassiz by the Buffalo River extends about 5 miles southwestward from Muskoda, forming a continuously descending plain of stratified sand and fine gravel, declining from 1,100 feet near Muskoda to 1,073 feet at its southwestern limit in the north part of section 34, Riverton. Here and northward along a distance of 3 miles to the Buffalo River this delta plain is terminated by a steep slope, 25 to 40 feet high, like the face of a terrace. The outer portion of the original delta, beyond this line, has been carried away by the waves and shore currents of the lake when it stood at the lower levels marked by the Norcross and Tintah beaches, as shown in fig. 11.
FIG. 11--Section across the delta of the Buffalo River. Horizontal scale, one-half mile to an inch.
Northern Pacific Railroad track at Muskoda, 1,090 feet. Threshold of church a quarter of a mile southeast from Muskoda depot, 1,113 feet. Beach here and for a third of a mile south to the Buffalo River, as also at the excavation for the railroad, 25 rods north of the church, nearly uniform elevation of its crest, 1,113 to 1,114 feet. The beach is 35 rods wide, rising 14 or 15 feet in a gentle swell above the edge of the delta of modified drift on the west and descending the same amount to the depression at its east side. It is made up of interstratified gravel and sand, the former prevailing, including pebbles up to 3 or 4 inches and rarely 6 or even 9 inches in diameter, all waterworn. Half or two-thirds of these pebbles and cobbles are limestone. No bowlders occur here, nor are they found in any of the beach deposits of Lake Agassiz.
[p.291] The area of the Buffalo delta extends 7 miles from north to south, with a width of 2 to 3½ miles. Its average thickness is probably about 50 feet, and its volume is therefore approximately one-sixth of a cubic mile. It would make a very sightly hill if its material were piled on the flat plain of the Red River Valley, for it would cover a circle 2 miles in diameter and rise to a peak about 900 feet high. Lying on the slope which rises east from this valley, however, and being spread over a considerable area with comparatively little thickness, its mass does not especially command attention until investigation reveals that it came almost wholly from drift that was contained within the ice-sheet, being deposited here by the streams from its melting.
The existence of well-defined and conspicuous delta deposits having the altitude of the Herman beach, where the Buffalo and Sand Hill rivers enter the east side of the area of Lake Agassiz, while no such deposits are found where other streams of equal or larger size enter this area, as the Red River, the Wild Rice, and the Red Lake River, seems explicable only by the derivation of the gravel and sand forming these deltas mostly from the englacial drift of the melting ice-sheet upon the adjacent area at the east. Comparatively small tribute was brought into this glacial lake from the erosion of the stream valleys after their areas became uncovered from the ice, excepting where it received the very large rivers flowing from other glacial lakes at the west. Here and there, because of irregularities in the outline of the ice-sheet, by which the drainage of its surface was poured down upon certain limited tracts and was discharged thence along the courses of now existing streams, as the Buffalo and Sand Hill rivers, and because the retreat of the ice was now rapid and anon was interrupted by halt or readvance, with the accumulation of moraines, much of the material which had been inclosed within the basal part of the ice-mass seems to have been washed away by its streams and carried into Lake Agassiz to form deltas.
When such glacial streams encountered no lake to receive their tribute, and flowed far before reaching the sea, the gravel, sand, and fine silt or clay which they brought were spread by the rivers along their courses as plains of modified drift. In some instances, since the ice-sheet disappeared and [p.292] the drainage from it ceased, these plains are left far from any important stream. Similarly, on the west side of Lake Agassiz, a large delta extending southward from the Elk Valley was deposited by a proportionally large river flowing from the ice-sheet, but no considerable river now enters the lake area there.
Opposite to the Buffalo delta, within a distance of about 30 miles to the east, the ice front was indented by a great embayment or reentrant angle at the time of formation of the eighth or Fergus Falls moraine. While the ice border was receding from the seventh or Dovre to the Fergus Falls moraine, the conditions of its melting were probably unfavorable for the formation of deltas in this glacial lake; but during the accumulation of the Fergus Falls moraine the drainage from the ice border converged toward the Buffalo River and caused its delta to be formed. Again, when the ice-sheet had retreated another stage and was forming its ninth or Leaf Hills moraine, this indentation of the ice front, having fallen back about 40 miles northward from its former position, sent its glacial streams to the Sand Hill River, and a second delta was brought into the lake.
In the same manner, the much larger Sheyenne, Elk Valley, Pembina, and Assiniboine deltas, brought into Lake Agassiz from the west and having likewise the height of the early Herman beaches, are referable chiefly to the drainage from the melting ice-sheet, and in less measure to erosion of the river valleys. The material of all the deltas of this lake is principally modified drift, rather than alluvium like that which the streams now transport and spread over their bottom-lands at every stage of flood.
(PLATE XXV.)
In the next 2 miles north of Muskoda the crest of the Herman beach ridge ranges mainly from 1,113 to 1,125 feet above the sea; at its lowest depression, about 1 mile north of Muskoda, its height is 1,105 feet; at William Perkins's house, in the southeast quarter of section 30, Cromwell, 1,122 feet; an eighth to a third-of a mile south-southeast from Mr. Perkins's, 1,130 feet. A nearly or quite continuous depression, from a fifth to [p.293] a third of a mile wide, lies at the east side of this beach, declining in elevation from 1,118 feet near Mr. Perkins's house, to 1,100 feet at Muskoda. This distance is about 3 miles.
The surface of Lake Agassiz in its maximum stage was, at Muskoda, 1,105 feet, very approximately, above our present sea-level. Within 5 to 10 miles northward its height seems to have been 1,110 to 1,115 feet.
Beach through the north half of section 30, Cromwell, 1,128 to 1,131 feet, and through the west part of sections 19 and 18, same township, 1,125 to 1,130 feet, composed of sand and fine gravel, not generally in a typical ridge, but often with a depression 2 to 5 feet lower eastward and bounded on the west by a descent of about 30 feet within an eighth of a mile. A surface of slightly undulating till rises very gradually from this beach eastward.
Herman beach at a high portion in or near the southeast quarter of section 1, township 140, range 46, 1,136 feet. For a mile next south from this point it is a finely rounded ridge of gravel, rising northward from 1,130 to 1,136 feet. The depression at its east side is 4 to 6 feet lower; then the surface gently rises at a quarter to a third of a mile from the beach to 1, 135 or 1,140 feet, beyond which eastward this nearly level but slightly undulating expanse of till rises only 5 or 10 feet per mile. Beach a fourth of a mile north-northeast from the high point mentioned, probably in the northwest quarter of section 6, Cromwell, 1,128 to 1,127 feet. This is an ordinary beach ridge of gravel and sand, with a depression of 2 or 3 feet next east.
Near the south line of section 29, Keene, both the Herman and Norcross beaches, here about two-thirds of a mile apart, are intersected by a watercourse. At its north side the upper or Herman beach, near the east line of section 29 and in the northwest quarter of section 28, consists of two well-marked ridges of gravel and sand, some 30 rods apart and about 10 feet above the land eastward and between them. These ridges unite in or near the southwest quarter of the southwest quarter of section 21, at the height of 1,130 to 1,132 feet. Beach three-fourths of a mile farther north probably near the north line of section 21, a typical gravel ridge, 1,134 feet, 10 feet above the land next east; but a sixth of a mile farther northeast this beach ridge is depressed to 1,123 feet.
[p.294] A lower beach, contemporaneous with the Herman beach farther south, but formed when the surface of the lake in this latitude had fallen slightly from its highest level, is finely exhibited at a distance of one-third to two-thirds of a mile west from the upper beach, through the 4 miles from the south side of section 20 to the northeast corner of section 4, Keene. The elevation of this secondary beach in the south part of section 20 is 1,115 feet; thence to a stream near the east line of the southeast quarter of section 17, 1,118 to 1,123 feet; at each side of this stream, 1,118 feet; northward, in the northwest part of section 16 and in the southwest quarter of section 9, 1,118 to 1,121 feet; and in the north part of section 9, 1,121 to 1,127 feet.
Upper beach through the west part of section 10, Keene, 1,130 to 1,137 feet, increasing in height from south to north. This is a typical beach ridge of gravel, with a rather abrupt descent on its east side to land 6 or 8 feet lower, which thence ascends with a slightly undulating surface eastward. The elevation of the upper beach in this township, 1,123 to 1,137 feet, shows that the height of Lake Agassiz here, during its maximum stage, was about 1,120 feet. The secondary beach was made by the lake after it had fallen 6 to 10 feet.
In section 3, Keene, the crest of the upper beach is at 1,134 to 1,137 feet, 10 feet above the land next east; and the top of the secondary Herman beach, parallel with this and about three-fourths of a mile distant to the northwest, in sections 4 and 34, is at 1,123 to 1,127 feet, being thus 10 feet lower than the highest parts of the eastern beach. Extensive sloughs, inclosing lakelets, lie between these beaches in sections 34 and 35, Hagen, at an elevation of 1,115 to 1,120 feet, but sinking northward to 1,105 feet. The secondary beach continues to the northeast corner of section 26, declining in height northeastward as it approaches the South Branch of the Wild Rice River, being at 1,125 to 1,115 feet.
Upper beach in section 35 and in the south part of section 25, Hagen, 1,140 to 1,142 feet. This is a typical beach ridge of sand and gravel, about 30 rods wide, with the land next southeast 5 to 8 feet lower, and divided from the secondary beach northwesterly by a slough about 1 mile wide, this slough being at 1,115 to 1,105 feet.
[p.295] Crest of beach at B. O. Helde's house, in the south half of the southwest quarter of section 30, Ulen, 1,138 feet. The flat expanse of the Red River Valley reaches east on the South Branch of the Wild Rice River to section 16, Hagen, probably being there about 975 feet above the sea, or 160 feet below this upper beach of Lake Agassiz, 4 or 5 miles southeast.
Beach through sections 30 and 29, Ulen, extending 1½ miles east-northeast from Mr. Helde's to the South Branch of the Wild Rice River, in a low, gently rounded ridge of gravel, 30 rods wide, 5 to 8 feet above the area of till next southeast and about 15 feet above the surface close at its northwest side, 1,138 to 1,142, mostly 1,140 feet.
South Branch of Wild Rice River, in the southwest quarter of section 21, Ulen, 1,095 feet. The beach is developed as a typical gravel ridge, in or near the west half of section 16, Ulen, a half mile to 1½ miles north of the South Branch, with its crest at 1,140 to 1,143 feet; surface of till an eighth to a quarter of a mile next east, 1,135 feet. Farther east the slightly or moderately undulating expanse of till has an average ascent of about 10 feet a mile for 15 miles to the base of the high land at the White Earth Agency, which is dimly visible, blue, close to the horizon. Westward the surface gradually descends to the Norcross beach, nearly 60 feet lower, which is the farthest land in sight in that direction, about 3 miles distant, beyond which lies the flat Red River Valley.
Entering Norman County, an unusually high portion of the Herman beach is found in or near the southeast quarter of the southeast quarter of section 33, Home Lake, having its crest at 1,149 feet. It holds this elevation for an extent of some 20 rods, on each side of which its height is mostly from 1,139 to 1,145 feet. Its material is coarse gravel, principally limestone, with pebbles and cobbles up to 4 and 6 inches in diameter. Surface close east of this beach, 1,137 feet. A slight swell above the general descending slope westward, about 2 miles distant, has a height very nearly 1,125 feet. This may be the continuation of the secondary beach that was seen in Keene Township. It hides the view farther west, except from the highest point of the beach (1,149 feet), where the distant belts of timber along the Red and Wild Rice rivers are visible.
Beach at J. T. Huseby's house, in the northwest quarter of section 26, Home Lake, 1,147 feet; through 1¼ miles next north, in the northwest [p.296] quarter of section 26 and the west part of section 23, forming a broad, low ridge of gravel and sand, 1,145 to 1,149 feet. In or near sections 17 and 16, Flom, a prominent, massive hill, called "Frenchman's Bluff," of somewhat irregular form, composed of morainic till, rises 150 feet or more above this beach.
Through the west part of the northwest quarter of section 14, Home Lake, the beach is mostly a typical gravel ridge, with its crest at 1,147 to 1,152 feet. In the northwest quarter of section 11, same township, it curves northeastward and attains an unusually massive development, its crest being at 1,150 to 1,158 feet, rising 15 feet above the land next southeast and 25 or 30 feet above the border of the area of Lake Agassiz at its northwest side.
Crest of beach, a well-marked gravel ridge, near the southwest corner of section 1, Home Lake, 1,156 feet, and an eighth of a mile east-northeast from this, 1,150 feet. J. G. Aurdal's house, foundation, in the northeast quarter of section 6, Flom, 1,148 feet. This is situated on the beach, which here is a deposit of gravel and sand 8 feet or more in depth, lying upon a slope of till that ascends southeastward. Anton Johnson's store, foundation, on this beach, in the southeast quarter of section 31, Fosum, 1,142 feet. Creek flowing northwesterly between the last two, about 1,105 feet. Wild Rice River, 2 miles north of Johnson's store, approximately 1,050 feet.
Secondary Herman beach, a well-marked, broad, smoothly rounded gravel ridge, extending from southwest to northeast, crossed by the township line road at the north side of the northeast quarter of the northwest quarter of section 2, Home Lake, 1,137 feet. It is about 30 rods wide, and rises 5 to 10 feet above the depression at its southeast side.
A broad belt of timber borders the Wild Rice River, lying mostly on its north side, in Fosum and Wild Rice townships, and at the time of this survey, in 1881, no road or bridge afforded a crossing here. Therefore this series of levels was resumed north of the Wild Rice River by starting from Rolette station of the St. Paul, Minneapolis and Manitoba (now the Great Northern) Railway, 892 feet above the sea, near the middle of section 17, Lockhart, about 1½ miles north of the Lockhart farm. Proceeding [p.297] eastward from this point, the first observations of the upper beach were in Waukon, Sundal, and Garfield townships.
This beach is intersected by the Wild Rice River near the middle of Fosum, and thence it passes north-northwesterly through the west part of Waukon. In sections 7 and 6, Waukon, it is a low, smooth ridge of gravel and sand about 25 rods wide, rising 5 to 10 feet. In the west half of this section 6 and in section 36, Sundal, the old Pembina trail lies on it.
About 2 miles west of the upper beach, a secondary Herman beach, of similar material and contour, probably 20 feet lower, was observed a few rods east of the stake at the middle of the north side of section 14, Strand, having a height of 6 to 8 feet above its base, with a smaller ridge of sand and gravel, 3 feet high above its base, close west of this stake. Again, a half mile farther west, in the northeast corner of section 15, Strand, another Herman beach, probably 10 feet below the last, was noted, having a height of 4 or 5 feet above its base.
Traveling northwestward along the Pembina trail, the upper beach ridge was not distinctly observed after leaving section 36, Smidal, until it is again occupied by the trail in section 9 of this township. The intervening 3 miles are flat and nearly level. Probably the beach, less noticeable than visual, lies within a half mile or 1 mile east of the trail here. In the eastern part of section 9 this beach is about 25 rods wide, rising 5 feet from its east side, and descending 10 feet to its western base, which was the margin of Lake Agassiz.
Thence the upper beach extends nearly due north through the east edge of section 4, Sundal, and section 33, Garfield. In the east edge of the southeast quarter of section 28 and the west edge, of the northwest quarter of section 27, Garfield, it is a typical ridge of gravel and sand, with its crest 1,166 to 1,173 feet above the sea. There is a gradual descent toward the west. The depression on the east is a sixth to a fourth of a mile wide, sinking 6 to 10 feet below the beach. Farther eastward the land is moderately undulating till, rising 20 to 30 feet above the beach and bearing frequent groves of small poplars, bur oak, and canoe birch.
Water in the Sand Hill River at the ford of the old Pembina trail, in the west part of section 28, Garfield, ordinary low stage, July 26, 1881, 1,071 feet.
When Lake Agassiz stood at its greatest height, the Sand Hill River brought into its margin a delta 6 miles long from south to north and 3 miles wide, reaching from the upper beach to the west side of Garfield and Sundal townships (fig. 12). This deposit of stratified gravel and sand has about an equal area and thickness with the delta of the Buffalo River at Muskoda. Its surface descends slowly westward and is crossed by the lower Herman and the Norcross shores, though these lake levels are not generally traceable. The Tintah shores pass along its western margin, which in some portions was worn away to a low escarpment, steeper than its original frontal slope, while the eroded sand and gravel, after being carried some distance southward, but not wholly beyond the delta, were deposited in beach ridges. Upon the delta plain many dunes of small and large size, seen from a distance of 10 or 12 miles across the lower expanse at the west, have been heaped up by the winds, probably mostly before vegetation had spread over this area after the withdrawal of the glacial lake.
FIG. 12.--Section across the delta of the Sand Hill River. Horizontal scale, one-half mile to an inch.
As was stated on page 291, in the description of the Buffalo delta, both these river deposits in the edge of Lake Agassiz seem attributable to conditions of the recession of the ice-sheet. Their gravel and sand were doubtless mainly englacial drift and were brought into this lake by streams which had gathered their freight upon the ice surface during the time of formation of terminal moraines. One of these glacial rivers, supplying a part or perhaps nearly all of the Sand Hill delta, flowed from an angle of the ninth or Leaf Hills moraine in a channel which has been traced 16 miles to its junction with the Sand Hill River, as described on page 164. Its sand and fine silt were carried more than 30 miles by the strong current [p.299] of the river in its irregular course before they were deposited in Lake Agassiz, where they at once settled to the bottom of the still water.
In the south half of section 32, Garfield, and in a belt which thence extends approximately north and south, the surface of this delta, as it was originally deposited, falls toward the west with a slope of 25 or 30 feet in 1 mile from 1,125 or 1,130 feet to about 1,100 feet above the sea. Beneath this plane, however, channels have been eroded by the winds, and sand hills 25 to 75 feet above it have been blown up in irregular groups and series, scattered over a tract about a mile wide and extending 3 or 4 miles southward from the Sand Hill River, in section 29, the northeast part of section 30, and in sections 31 and 32, Garfield, and reaching southward in sections 5 and 8, Sundal. The most southern of these hills is an isolated group in the east part of the northeast quarter of section 18, Sundal. Another isolated group lies north of the Sand Hill River, in the northwest quarter of section 16, Garfield. These sand dunes are in part bare, being so frequently drifted by the winds as to allow no foothold for vegetation; other portions are clothed with grass or with bushes and scanty dwarfed trees, including bur oak, the common aspen or poplar, cottonwood, green ash, black cherry, and the frost grape.
Elevations of the highest points of these dunes, in order from south to north, are approximately 1,190, 1,180, and 1,200 feet. The highest dune appears to be in or near the east half of the northeast quarter of section 30, Garfield.
Secondary Herman beach, a smoothly rounded ridge of gravel and sand 10 to 15 feet high above the adjacent level, 1,148 to 1,153 feet above the sea, about three-fourths of a mile east of the old Pembina trail, in the west half of sections 21 and 16, Garfield, extending 1½ miles north from the Sand Hill River to the cluster of dunes in the northwest quarter of section 16.
(PLATE XXVI.)
The upper Herman beach, the first of the series which was formed in the vicinity of Maple Lake contemporaneously with the single Herman beach farther south, runs approximately from south to north, through or [p.300] near the northeast corner of section 4, Garfield. It is a smooth gravel ridge, in some parts hidden by scattered groves, with its crest 1,165 to 1,175 feet above the sea. Farther east is a large area of woodland. The second Herman beach, in the east part of section 5, this township, and section 32, Godfrey, about a mile west from the upper beach, has a height of 1,149 to 1,153 feet, being a ridge of gravel and sand about 40 rods wide, with very gentle, prolonged slopes toward both the east and west. Natural surface at the northeast corner of section 32, Godfrey, 1,146 feet. Third Herman beach, running north, in the northwest quarter of section 5, Garfield, and the west part of section 32, Godfrey, a half or two-thirds of a mile west from the last, 1,130 to 1,135 feet, consisting of a distinct ridge in its southern part, but farther north being a flat area of gravel and sand, slightly elevated above the land next east.
Second Herman beach, a broad, low ridge of gravel and sand, extending north-northeast through section 28, Godfrey, from its southwest corner to its north line, 1,148 to 1,150 feet. The northward continuation of this beach is a low, flattened ridge, the western one of two parallel ridges of gravel below that of the upper beach, extending northeasterly and northerly through or near the west edge of section 10, Godfrey, 1,150 to 1,154 feet. Through the next 3 miles in section 3, Godfrey, and in the east part of sections 35 and 26 and the northwest quarter of section 25, Tilden, it is a prominent beach ridge, with its crest at 1,153 to 1,161 feet, somewhat steep on its east side, which descends about 10 feet to a belt of lowland and marsh that divides it from the parallel beach a quarter to a third of a mile east.
The eastern one of these parallel beach ridges is only 8 or 10 feet below the average elevation of the upper beach. It probably marks a slight rise of the land here; but no corresponding beach formation has been observed on this latitude in North Dakota. It is clearly continuous 8 miles, the first 4 miles extending northerly and the next 4 miles easterly. These parts are connected in section 25, Tilden, by a graceful curve, that portion of this beach and its extent thence eastward being known as the "Attix ridge," from Henry and William Attix, brothers, who have built their houses upon it. In its northward course, nearly through the middle of sections 10 and [p.301] 4, Godfrey, its crest is at 1,158 to 1,163 feet; in the west edge of section 36, Tilden, and along its curved course to the northeast and east at the west and north sides of section 25 and in the southeast part of section 24, Tilden, 1,163 to 1,168 feet, and in sections 21 and 22, Grove Park, 1,171 to 1,173 feet. A slough, a third to a half of a mile wide, extends along the east side of this beach in section 3, Godfrey, and in the southeast part of Tilden, having a height of 1,155 to 1,160 feet.
Upper beach in the southwest quarter of section 11, Godfrey, forming a plain of stratified gravel and sand a quarter or a third of a mile wide from east to west, 1,168 to 1,173 feet. This beach near the south side of section 11 becomes a distinct gravel ridge of the usual character, about 25 rods wide, with its crest at 1,173 feet, bordered by a slough 20 to 40 rods wide at its east side. About a third of a mile farther southeast and some 50 rods west of the southwest extremity of Maple Lake, in section 14, Godfrey, the elevation of this beach ridge is 1,175 to 1,178 feet.
Maple Lake, water surface July 28, 1881, 1,169 feet. This lake, 6 miles long and averaging about a half mile wide, has a maximum depth of 20 feet near its southwestern end, and is mainly 10 to 15 feet deep along its central portion.
Upper beach, top of its well-marked gravel ridge in the east edge of the northeast quarter of section 3, Godfrey, about 20 rods north of Mr. Horton's, 1,180 feet. Beyond this point, through its next 2½ miles, curving from a northward to a northeastward and eastward course, this upper beach of Lake Agassiz is magnificently exhibited, forming a massive, gently rounded ridge of gravel and sand about 30 rods across, with its crest 1,178 to 1,186 feet above the sea. A view of this beach ridge is given in Pl. VI (page 26), taken on its top, near the south line of the southeast quarter of section 35, Tilden, and looking northeastward along its course. It is bordered on the southeast side by a tract of slightly undulating till 10 to 15 feet lower, mostly covered with small timber and brush and holding frequent sloughs and lakelets in its depressions. The top of the beach is not wooded, but small trees and bushes originally encroached upon its slopes. A road extends along the crest of its curving portion for a distance of about a mile through section 36, Tilden.
[p.302] The marsh which borders the northwest side of the northeast part of Maple Lake shows a descent of 5 to 7 feet northwestward, or away from the lake, in its width of 1 to 1½ miles. Maple Lake is prevented from flowing in this direction by a beaver dam near the lake. The creek draining this marsh where it intersects the upper beach near the east line of the northeast quarter of section 27, Grove Park, has a height of 1,163 feet. Here the beach skirting the north side of the marsh is a flat deposit of gravel and sand, a fourth to a half of a mile or more in width, highest next to the marsh, above which it rises 5 to 8 feet in a moderate slope. Its elevation in the north half of sections 26 and 27 is 1,169 to 1,172 feet, being even 1 or 2 feet lower than the Attix ridge, which lies some two-thirds of a mile farther north, in the south half of sections 21 and 22. This belt of beach gravel and sand continues 6 miles in a nearly due-east course, and beyond that it extends still eastward along the north side of a great tamarack swamp, which begins in section 34, Badger, and is said to be 8 miles long. Maple Lake and this tamarack swamp hold the same relation to the upper beach ridge, which was a barrier between them and Lake Agassiz and which now wholly or partially obstructs the drainage of these areas.
Third Herman beach, a small ridge of gravel and sand, extending from southwest to northeast, 8 to 10 rods wide, and rising 4 or 5 feet, crossed by the Crookston road in the southwest quarter of section 23, Tilden, and seen to reach at least a mile each way from this road, 1,146 to 1,149 feet.
Natural surface at the southeast corner of section 15, Tilden, 1,134 feet.
Fourth Herman beach, crossed by the road to Crookston and Red Lake Falls near the center of the southeast quarter of this section 15, 1,132 to 1,134 feet. This is a well-marked gravel ridge, mainly single, but twofold where it is crossed by this road. The distance of 1 mile here between these third and fourth Herman beaches consists of till, with a nearly smooth surface, which has bowlders up to 3 and rarely 5 feet in diameter quite numerously scattered over it. Southeastward from the third to the first or upper beach the surface mostly is sand and gravel, with no bowlders.
A portion of a shore-line of Lake Agassiz, probably the highest in the Herman series of beaches, has been observed on and near the southwest line of the Red Lake Indian Reservation, between Hill and Lost rivers. It was seen near the north side of sections 31 and 32, and in the central part of sections 27 and 26, township 150, range 40, also for a mile or more thence eastward in the reservation, being 15 to 20 miles east-northeast of Maple Lake. The area is mostly prairie, and the beach is well exhibited. In the southwest part of township 150, range 40, the beach ridge of coarse gravel runs along the northern border of a roughly morainic belt, which is a half to two-thirds of a mile wide. In sections 27 and 26, and onward in the Red Lake Reservation, the beach is a typical gravel and sand ridge, containing pebbles and cobbles, nearly all of Archean gneiss and crystalline schists, up to 6 and 8 inches in diameter. Its trend here for about 3 miles is nearly from west to east. On the south, within about 1 mile, is a typical morainic belt of many hillocks, knolls, and ridges, which cover a width of several miles and rise 100 to 150 feet above the beach and the low, nearly flat tract that was covered by Lake Agassiz on the north, consisting in large part of marshes, through which the Lost and Clearwater rivers flow westward in meandering courses.
About 25 miles farther east in the Red Lake Reservation the road from Red Lake to White Earth crosses a beach of Lake Agassiz, which is probably the highest, being a continuation of the foregoing. This beach runs nearly from west to east, and is approximately 40 feet above Red Lake, or 1,210 feet above the sea. It is a ridge of sand and fine gravel, crossed by the road about 2 miles southwest from Big Rock Creek and Shell Lake. A grove of red pines grows on the beach, but the till on each side bears white pines. Following the road to the southwest, a belt of kames is entered about three-fourths of a mile from the beach, which continues to Sandy River, having a surface of many knolls and short ridges, with no observable parallelism in their trends, the crests being 10 to 20 feet above the inclosed hollows.
[p.304] The most eastern observation of the upper shore-line of Lake Agassiz in northern Minnesota is by Mr. Horace V. Winchell, on the Bowstring River, more commonly known as the Big Fork of Rainy River, some 60 miles east of Red Lake. In his description of the ascent of this stream Mr. Winchell writes as follows of the locality, probably about 1,250 feet above the sea, where the surface changes from a smooth contour on the north, indicating lacustrine action, to a more undulating and rolling contour on the south, above the level of Lake Agassiz:
At the end of 7½ miles the foot of a rapid nearly one-half a mile long is reached. At the foot of it is a bank of gravel and sand [probably the beach of Lake Agassiz] . It is a very different sort of bank from those seen below here. It is stratified, or partially so, but not horizontally nor all in the same direction. It looks like a stratified river deposit. Under it crops out a little fine bluish-gray clay, of which only a foot or two can be seen. This is supposed to be Cretaceous. * * * There are many limestone pebbles in the bank above the clay, but no shale is seen in it.
This rapid is over an immense number of bowlders. Most of them are hornblendic gneiss, but other rocks are frequent. Many of the bowlders are large and stick up several feet above the water. A short distance up the rapid is a small island which seems to be made of bowlders and is covered with trees and bushes. * * *
Above the rapids quantities of bowlders are seen, while below only a few were encountered. The country does not seem to be of one general level, as before, but is knolly. The banks are of sand and gravel and contain much more gravel than those below the rapids. This is about 95 miles up the river, probably in township 62, range 25. It seems probable that the rapid mentioned above is on the boundary or shore of the glacial Lake Agassiz, and that all of the river below this rapid is included in the ancient basin.(2)
The recent survey for the Duluth and Winnipeg Railroad, passing northwest by the east end of Red Lake and the southwest side of the Lake of the Woods, shows that the former of these lakes lies about 40 feet and the latter somewhat more than 150 feet below the highest level of Lake Agassiz. The height of Red Lake above the sea is ascertained to be 1,172 feet, and of the Lake of the Woods, in its stages of low and high water, 1,057 to 1,063 feet. Northeast of Red Lake the Tamarack River drains a large tract of tamarack, spruce, and arbor-vitæ swamp, which reaches to [p.305] the divide between the Tamarack River and the West Branch of the Bowstring River (more commonly called the Big Fork), tributary to Rainy River, the height of the divide being only 15 to 20 feet above Red Lake. Similar low swamp land forms nearly the whole northern and northwestern shore of Red Lake and is crossed by this railroad survey continuously along its first 18 miles beyond Red Lake; but at a distance of 29 miles from the lake the profile shows an ascent crossing the highest beach of Lake Agassiz, which there is 1,215 feet above the sea. The next 17 miles of the profile extend across the northeastern edge of a large island of Lake Agassiz, rising on that line to a maximum height of 1,283 feet, with a moderately undulating drift-covered surface. In the next 15 miles, which comprise the descent on a similar but smoother drift surface from the highest shore of Lake Agassiz to the War Road River, an affluent of the Lake of the Woods, the profile crosses a succession of ten lower beaches of Lake Agassiz, marking stages in the gradual uplifting of the land and subsidence of the lake, their altitudes above the sea being 1,196, 1,172, 1,156, 1,143, 1,127, 1,116, 1,106, 1,099, 1,093, and 1,087 feet.
These data show that Lake Agassiz in its highest stage had a large island northwest of Red Lake, comprising the headwaters of numerous streams flowing outward from it to the Lake of the Woods, Rainy River, Red Lake, the Red Lake River, and the Red River of the North. This island had probably a diameter of 40 miles or more, with an area exceeding 1,000 square miles, of which apparently more than half is in Beltrami County, the portion farther west being chiefly in Marshall County, Minn. For this tract, which had before been supposed to be comparatively low and perhaps wholly beneath the highest level of Lake Agassiz, the name Beltrami Island is proposed, in recognition of the exploration of the region of Red Lake and the Julian or most northern sources of the Mississippi by Beltrami in 1823.(3) As Prof. N. H. Winchell wrote in the historical sketch here cited, this district "is still nearly as wild and uninhabited as when Mr. Beltrami passed through it." The limits of Beltrami Island are shown approximately on Pls. X, XXII, and other maps in this volume.(4)
[p.306] This island lies in the course of northwestward and northward continuation of the Mesabi or eleventh moraine of the series mapped in Minnesota, which next east from the narrows of Red Lake, rises very prominently to a height of 150 to 200 feet for a distance of about 10 miles upon the peninsula dividing the northern and southern parts of the lake. Like nearly the entire western half or two-thirds of Minnesota; this whole region is deeply drift-covered. No outcrops of the bed-rocks have yet been found on the large portion of the Red River basin lying in Minnesota; but the conspicuous escarpment of Cretaceous shales, overspread by drift, along the west border of the Red River Valley, wells penetrating to Cretaceous beds along this great valley plain, and the topographic features of the land rising eastward from it with nearly the same rate of ascent as on the west, lead to the belief that the eastern, like the western, border of this wide valley is formed by an escarpment of Cretaceous shales beneath the drift, and that the moderately elevated area of Beltrami Island consists of these shales enveloped by the glacial and modified drift.
FROM LAKE TRAVERSE NORTHWEST TO MILNOR.
From the southern extremity of Lake Agassiz, in section 18, Leonardsville, Traverse County, Minn., the upper or Herman beach extends northwestward 75 miles to the most southern bend of the Sheyenne River, in Ransom County, N. Dak., and thence its course is nearly due north, but with slight deflection westward, to the international boundary. The mouth of Lake Agassiz was where now a slough 2 to 3 miles wide, with frequent areas of open water, tributary to the Bois des Sioux River, stretches northward from the northeast end of Lake Traverse. On the west side of this slough and of Lake Traverse bluffs of till rise 100 to 125 feet; their tops and the rolling surface of till which extends thence westward are 1,070 to 1,100 feet above the sea.
The beginning of the upper or Herman shore-line west of the Bois des Sioux is in the northeast corner of South Dakota, in sections 10, 3, and [p.307] 4, township 128, range 48, nearly 2 miles south from the north line of the Sisseton and Wahpeton Reservation. The ancient shore rises with terrace-like steepness 20 or 30 feet above the surface of undulating till which borders it on the northeast. Its material is sand and gravel, with pebbles up to 1½ or 2 inches in diameter, about half of which are limestone. Beyond its steep margin this deposit of gravel forms a belt about a mile wide, approximately level, but with frequent short swells and low, flattened ridges, 5 to 10 or 15 feet above the intervening depressions. Its elevation is 1,060 to 1,070 feet above the sea, or from 90 to 100 feet above Lake Traverse.
For its first 3 or 4 miles the terrace-like lakeward margin of this belt of sand and gravel sweeps with a gentle curve westerly and northerly to a point in the southwest quarter of section 34, township 129, range 48, where it turns quite abruptly, taking a nearly due-west course for the next 3 miles to the west side of section 31 of this township.
In the northwest quarter of section 3, township 128, range 48, a third of a mile east of W. J. Allen's house, the ascent at the margin of this deposit is about 10 feet, to an elevation of 1,060 feet, approximately. The belt of sand and fine gravel is here about a half mile wide. Occasional hummocks, rising 5 to 10 feet and 50 to 100 feet long, which were observed on this part of the belt, appear to have been heaped up by the wind before the protecting mantle of grass and other herbaceous vegetation was spread over it.
Where this formation enters North Dakota, in the southeast quarter of section 32, township 129, range 48, similar dunes, 1,075 to 1,080 feet above the sea, have been excavated for use as plastering sand. Nearly all portions of this tract, and even its dunes, are now covered with a black soil and plentiful vegetation; but certain species preferring dry, sandy soil, as the dwarf rose (Rosa arkansana Porter), grow in greater abundance on the sand and gravel belt, and especially among its hummocks and hollows, than on the flat or slightly undulating surface of till at each side.
The inner margin of this belt, marking the shore of Lake Agassiz at its maximum stage, passes in its western course about 60 rods north of the southeast corner of section 32 and turns again to the northwest near [p.308] the middle of the west side of section 31, township 129, range 48. At the latter locality it is a low, wave-like ridge of sand and fine gravel, about 1,060 feet above the sea. On the south it is bordered by land 3 to 5 feet lower for a width of 1½ miles. J. R. Grimesey's well, 13 feet deep, at the southwest corner of section 31, on this low tract outside the beach ridge, encountered only very fine stratified sand, irregularly laminated and containing numerous tubular limonitic concretions. Farther to the southwest and west, a gently undulating surface of till, scarcely higher than the beach of Lake Agassiz, stretches away several miles, beyond which the highland of the Coteau des Prairies is seen in the far distance.
The Herman beach crosses township 129, range 49, in a diagonal course, entering it a half mile north of its southeast corner and running northwest to the north side of sections 5 and 6. In section 23 and the northeast part of section 22, its elevation is about 1,055 feet, but its dunes rise 3 or 4 feet higher. At the middle of the north side of section 16 it is a ridge of sand and fine gravel about 8 rods wide, rising 4 to 6 feet above the land on each side. Its crest here and for a mile to the southeast and northwest is 1,060 to 1,065 feet above the sea. Northeastward the surface falls about 20 feet in the first mile. On the southwest side of this distinct beach ridge, a smooth, slightly undulating tract 1½ to 2 miles wide, extending through this township, consists of sand and fine clayey silt. Its elevation varies from 1,055 to 1,080 feet, attaining the latter height in the northwest part of the township. This belt, with its continuation southeastward, previously described, was doubtless covered by Lake Agassiz before the erosion of its outlet to the level of the Herman beach; but its stratified sand and silt appear to be modified drift deposited by streams from the melting ice-sheet. The glacial recession here was from southwest to northeast, and this was probably an avenue of drainage during a short time, as was shown on page 150, till the continued retreat of the ice left a considerable expanse of water, the beginning of Lake Agassiz, between itself and the shore.
In the north part of sections 5 and 6, township 129, range 49, and in sections 31 and 32, township 130, range 49, this beach consists of two or [p.309] three parallel wave-like ridges of gravel and sand, divided by depressions an eighth to a quarter of a mile wide and T) to 10 feet lower.
This belt reaches north to the Lightnings (or Thunders) Nest,(5) a massive dune of fine sand (Pl. VII, p. 28), partly bare and now wind-blown, but mostly covered with bushes and herbage, situated near the center of section 30, township 130, range 49. Its base on the south is 1,060 feet and its top 1,120 feet, approximately, above the sea. It covers a space about a quarter of a mile in extent from southeast to northwest, with nearly as great width, and rises in two summits of nearly equal height. The Lightnings Nest is the most prominent in a series of dunes, elsewhere rising only 10 to 30 feet, mostly grassed, which extends a mile or more to the southeast and is traceable several miles northwest to the east end of a very conspicuous tract of dunes 50 to 100 feet above the adjacent level, with summits at 1,100 to 1,150 feet above the sea, which stretches about 4 miles in a west-northwest course in the south part of township 131, range 50, 1 to 2 miles south of the Wild Rice River. By winds, eroding and drifting, these sand hills were heaped up from the Herman beach and its associated belt of modified drift, probably soon after the retreat of the ice, though their forms have been constantly changing since that time.
Outside the area of Lake Agassiz, the southwest part of Richland County is till, mostly undulating or moderately rolling, but in part prominently hilly, with rough morainic contour and abundant bowlders. Taylor Lake, approximately 1,050 feet above the sea, 2½ miles west of the Lightnings Nest, is a very beautiful sheet of water, bordered by a sandy shore and a large grove on the north, and by a shore of bowlders and morainic hills 50 to 150 feet above the lake on the west. These hills and most of the lakes farther west in this county have no timber. Northeastward the area that was covered by Lake Agassiz is mostly smooth and nearly flat till, with frequent marshy tracts called sloughs, but with only very rare and small lakelets.
Swan Lake, 3 miles long, reaches from section 3 to section 7, township 130, range 51, having an estimated height of 1,070 feet above the sea, with [p.310] undulating till 5 to 10 feet higher on the northeast and 10 to 20 feet higher on the south and west.
The Herman beach, a ridge of fine sand, 20 to 25 rods wide and about 3 feet high, near the south line of section 36, township 132, range 52, trends to the west-northwest, and has a height of 1,065 feet, approximately. On the north, the exceedingly flat plain of Lake Agassiz, sinking very slowly northeastward, reaches as far as the eye can see. On the South, flat land, covered by Lake Agassiz before the time of this beach, continues 1½ miles, ascending in that distance from 1,060 feet to about 1,080 feet, and moderately undulating till rises beyond to 1,100 and 1,125 feet.
One and a half miles north of this beach the Wild Rice River is crossed by a bridge near the center of section 25, township 132, range 52. The stream in its ordinary stage is 1 to 2 rods wide, with a depth of about 3 feet, and is filled with grass and rushes. Its bottom land, a sixth to a third of a mile wide, is about 10 feet higher and is annually overflowed by the high water in spring. Its bluffs rise about 40 feet above the river at low water, the elevation of their top and of the adjoining plain being, approximately, 1,050 feet. These bluffs and the surface from the Herman beach north to Elk Creek are till, but the country about Wyndmere and south to Elk Creek is stratified, fine clayey sand. Both formations have a very fertile soil, unsurpassed for wheat and all crops proper to this latitude. Elk Creek is a stream similar to the Wild Rice River, but smaller, and the width and depth of its valley are about two-thirds as great.
Northern Pacific, Fergus Falls and Black Hills Railroad, track at Wyndmere, 1,062 feet above the sea; at the Herman beach, 1½ miles west of Wyndmere, track 1,066 feet, and crest of the beach 1,068 feet, rising 8 feet above the adjacent land 20 rods away both east and west; surface along the railroad thence westward 8 miles, 1,062 to 1,066 feet, with Star Lake, a third of a mile in diameter on this level area, only 2 or 3 feet below the surrounding land close north of the railroad in section 5, township 132, range 52 a higher beach of Lake Agassiz crossed 3 miles east of Milnor, and therefore called the Milnor beach, crest and track, 1,085 feet, 4 or 5 feet above the adjoining land 10 rods away both east and west; [p.311] another beach ridge formed during the same stage of Lake Agassiz, a third of a mile farther west, crest and grade, 1,086 feet; land close east, 1,081, and west 1,087 feet; track at Milnor, 1,097 feet.
The Herman beach west and north of Wyndmere has an irregular surface, with frequent hummocks of sand heaped 5 to 10 feet above adjacent hollows. Most of these dunes are now grassed. From near Wyndmere this beach, with frequent small dunes, extends north through the west edge of township 133, range 51, and thence westerly to another tract of prominent dunes 50 to 100 feet above the adjacent surface, with their top at 1,100 to 1,150 feet, which extends about 10 miles in a west-northwest course from the southwest part of township 134, range 52, to the east part of township 134, range 54, terminating about 2 miles east of the Sheyenne River. Like the similar high dunes south of the Wild Rice River, these are mainly covered by herbage, bushes, and small trees; but many portions are now being drifted by the winds, so that they are wholly destitute of vegetation. These dunes mark the course of the Herman beach, here greatly increased in volume by delta deposits from the Sheyenne River.
Morainic knolls and hills, rising 20 to 50 feet with plentiful bowlders, lie close west of Milnor, extending in a belt from southeast to northwest. They are referred to the seventh or Dovre moraine, as described in Chapter IV. Near Lisbon, about 15 miles northwest from Milnor, some of these morainic hills are quite conspicuous, rising 100 feet or more above the surrounding country.
Evidence of a stage of Lake Agassiz 20 or 30 feet higher than that of the Herman beach is found, as before noticed, in many places along the southern part of its boundary in North Dakota. The portion of this glacial lake formed earliest by the recession of the ice seems to have reached from Lake Traverse to the Sheyenne River, and its level appears to have been then nearly that of the general surface and the top of the bluffs bordering Lake Traverse. An explanation of the conditions probably producing this Milnor stage of the incipient glacial lake, with the reasons why it was limited to a comparatively short extent on the southwestern border of the lake area, has been presented on pages 150 and 211.
(PLATE XXVII.)
The highest level of Lake Agassiz near Milnor is marked by the Milnor beach, already mentioned, where it is crossed by the railroad. This beach is fine clayey sand, in somewhat irregular and interrupted low ridges and terraces, abutting at the west on undulating till, which gradually rises 10 or 20 feet higher, while on the east a descent of 10 or 15 feet within about 20 rods is succeeded by a flat area, which thence sinks very slowly northeastward. The elevation of the Milnor beach at the railroad is 1,086 feet, and at Mr. G. V. Dawson's house, at the middle of the east side of section 22, township 133, range 54, 1,092 feet. Its course between these points is north-northwest, and this is continued to the mouth of a former channel of the Sheyenne River, near the center of section 4 in this township, 3 miles east from the most southern bend of the river.
During all the stages of Lake Agassiz the Sheyenne River brought into it much sediment, carrying the clay farther than the sand and gravel, which were laid down near the river's mouth. Extensive areas of these originally flat beds have been changed by wind action to irregular groups and belts of sand hills or dunes, which vary from a few feet to more than 100 feet in height above the surrounding level. Besides the large tract of these dunes before described east of the Sheyenne River, others of even greater extent and equally conspicuous border the river and reach 2 or 3 miles from it in the northeast part of township 135, range 54, and along its next 15 miles.
Watercourses formerly occupied by this stream are found west of the Milnor beach. One of them is marked by a sandy flat, which reaches from the present course of the Sheyenne River, in section 1, township 133, range 55, southeastward through township 133, range 54, to the vicinity of Milnor. Another runs from near the middle of the southwest quarter of section 32, township 134, range 54, about 1¼ miles east-southeast to the middle of section 4, township 133, range 54. This is a channel 30 to 50 rods wide, about 40 feet below a ridge of coarse gravel, which extends along its northeast side, dividing it from the lower area that was covered by Lake Agassiz and from the present valley of the river. The crest of the [p.313] ridge is nearly flat upon a width of 10 to 30 rods, and is 75 to 100 feet above the river, being highest westward. It contains pebbles and cobbles of all sizes up to 6 inches in diameter, about half being limestone and nearly all the others granitic. This ridge or plateau of gravel is a remnant of an old delta plain of the Sheyenne River, apparently deposited before the formation of the Milnor beach, above which it rises some 40 or 50 feet, which suggests that the deserted channel of that depth on its south side was probably eroded during the Milnor stage of Lake Agassiz. Similar gravel occurs on the side and verge of the bluff, 100 feet high, northwest of the Sheyenne River, in the southwest quarter of section 29, township 134, range 54, but a rolling surface of till extends thence northwest.
The height of the Sheyenne River in section 32, township 134, range 54, is 1,039 feet above the sea; and on the west line of the northwest quarter of section 29, township 135, range 54, 1,021 feet. Its bed through these townships is mostly 4 to 6 rods wide, with water 1 to 2 or 3 feet deep, and is strewn in many places with cobbles and bowlders up to 2 or 3 feet and rarely 6 or 8 feet in diameter. Its bottom land near the south bend, about a third of a mile wide, is 15 or 20 feet above the ordinary low stage of water, and during a term of fourteen years preceding this survey in 1885 it had not been overflowed; but driftwood, found by the first immigrants, proves that the river sometimes reaches this height. Bluffs of till here, in the southwest corner of township 134, range 54, rise 100 to 125 feet above the stream.
Bluffs of till close west of the Sheyenne River, in section 20, township 134, range 54, 1,100 to 1,110 feet; moderately rolling till a quarter of a mile farther west, 1,115 to 1,125 feet; same in sections 17 and 18, 1,090 to 1,130 feet; and on the east side of the river, in sections 21, 16, and 17, 1,085 to 1,075 feet, descending northeastward. Prominent swell of till west of the Sheyenne River, in the southeast quarter of section 30, township 135, range 54, having four aboriginal mounds on its crest, 1,113 feet; top of these mounds, 1,117 feet, very nearly. Highest portions of the area of undulating till seen westward from this section 30, 3 or 4 miles distant, 1,125 to 1,150 feet.
[p.314] Surface at Charles G. Froemke's house, in the northwest quarter of section 29, township 135, range 54, 1,075 feet; bottom land of the Sheyenne River close west, 1,039 to 1,029 feet; ordinary low water of the river, 1,021 feet.
Portion of area of Lake Agassiz, a strip a fourth to a third of a mile wide, west of the Sheyenne River, in sections 32 and 5, a half mile to 2 miles south of Mr. Froemke's, 1,065 to 1,075 feet. Herman beach one-fourth to two-thirds of a mile east of the Sheyenne River here and extending southeasterly toward the western limit of dunes in the east part of township 134, range 54, 1,073 to 1,079 feet. Crest of this beach, a low ridge of sand and fine gravel, at J. Altmann's house, near the middle of section 20, township 135, range 54, 1,073 feet. Within 10 or 15 rods east there is a descent of about 10 feet. This beach ridge runs north and northeasterly to near the northeast corner of this section 20, and thence it passes eastward about 3 miles, having an elevation of 1,075 to 1,065 feet to where it is intersected by the Sheyenne River, near the northeast corner of section 14. North of the river it continues about a half mile in section 12, its elevation being 1,065 to 1,070 feet, to the west end of a tract of dunes 25 to 100 feet above their vicinity, with summits at 1,100 to 1,150 feet, which extends thence about 15 miles eastward. This Herman beach was sufficient to turn the course of the Sheyenne River along its west and north side for a distance of 8 miles, from section 9, township 134, range 54, north and east to section 14, township 135, range 54, though it is only a ridge of sand and gravel 5 to 10 feet higher than the smoothed area of till, occasionally covered by 1 to 3 feet of sand, which lies west of it and in which the river has now cut its channel 50 to 60 feet deep.
Rolling surface of till in the south edge of section 9, township 135, range 54, 25 to 40 rods north of the Sheyenne River, 1,080 to 1,090 feet. Most of this section 9 is nearly level till at 1,080 to 1,085 feet, with occasional large hollows 20 feet lower. It seems to have been smoothed by Lake Agassiz at the time of the Milnor beach. Westward is slightly undulating till, having an elevation of 1,085 to 1,125 feet for 2 or 3 miles, as far as the surface lies within view.
[p.315] Herman beach in the northwest quarter of section 10, township 135, range 54, 1,075 to 1,080 feet. This is a deposit of gravel and sand extending along the verge of the plateau of till just described in section 9. Fifteen or 20 rods to the east the elevation is 1,065 feet, and it sinks slowly thence eastward to about 1,050 feet at the west base of the dunes in sections 12 and 1 of this township.
Lakelet back of this beach, situated in the east edge of the southeast quarter of section 4, township 135, range 54, about 50 rods long from south to north, 1,060 feet, being 25 feet below the average of the adjacent undulating till. Shallow lakelet 40 rods across, close east of the beach, a quarter of a mile east from the northwest corner of section 3, also 1,060 feet; adjoining land, 1,065 to 1,070 feet, excepting on the west, where the Herman beach has an elevation of 1,080 feet, with undulating till beyond it a few feet higher.
Herman beach at the middle of the west side of section 34, township 136, range 54, Sheldon, 1,082 feet; surface 25 rods east, 1,070 feet, thence descending slowly eastward. Here and for 1½ miles south, through section 3, this beach is a flattened ridge of sand and fine gravel, 25 or 30 rods wide, with a depression 3 to 6 feet deep along its west side. In the northwest quarter of section 28 its elevation is 1,080 feet.
Fargo and Southwestern Railroad track at Sheldon, 1,080 feet. Wells in Sheldon village are 10 to 15 feet deep; in sandy clay, free from gravel or bowlders, 6 to 10 feet, with sand below. These deposits belong to the Herman beach, which is here spread upon a width of about a half mile.
(PLATE XXVII.)
The deposition of the delta proper, and also of the fine lacustrine silt extending beyond its plateau to the Red River, took place mainly during the upper Herman stages. The plateau, gently descending eastward, is crossed by the Herman and Norcross shore-lines, and in part by the Tintah and Campbell shores on its eastern and southeastern border. From the Maple River 8 miles east to Leonard, however, and thence southeasterly about 25 miles, its margin has been eroded and changed to an abrupt escarpment, or at least a somewhat steep slope, by the lake waves during the Tintah, Campbell, and McCauleyville stages. This front of the delta, 75 to 25 feet above the flat low land of the Red River Valley adjoining its base, decreases in prominence as it is followed southward. It passes close north of Leonard and within a few miles west of Kindred, Walcott, Colfax, and Barrett, gradually ceasing as a notable feature farther south.
FIG. 13.--Section across the delta of the Sheyenne River. Horizontal scale, 6 miles to an inch.
A great portion, probably exceeding a half, of the Sheyenne delta, as of all the other large deltas of this glacial lake, is modified drift, which was brought down by glacial streams from the melting surface of the ice-sheet. The coarser gravel and much sand that were supplied from the ice to the head streams of the Sheyenne during the time of formation of its delta were deposited along the outer side of the great moraines, south of Devils Lake; the finer gravel and a great volume of sand were carried by the Sheyenne to this delta; and the finest silt and clay of the great glacial river were spread in the quiet water of the lake, over a much larger adjoining area of its bed, from near Breckenridge northward beyond the mouth of the Sheyenne.
[p.317] Much alluvium was also supplied from the erosion of the Sheyenne Valley, which, with that of the Big Coulee (the avenue of discharge from the glacial Lake Souris to the Sheyenne and Lake Agassiz), probably averages three-fourths of a mile in width and 150 feet in depth along a distance of 200 miles. This channel is cut in the drift sheet, mainly till, and in the underlying, easily eroded Cretaceous shales. The volume of the material supplied from it would be equal, according to these estimates, to about three-fourths of the Sheyenne delta, or perhaps three-eighths of both the delta and the finer clayey sediments that were deposited farther out in the lake. But the valley of the Sheyenne, in considerable portions of its extent, was also a preglacial valley. If it retained in a considerable degree its trough-like form beneath the ice-sheet, as was evidently true of the Minnesota Valley,(6) its erosion and its tribute to the Sheyenne delta would be less than the proportion estimated.
The Herman beach, terrace-like, at Hugh McIntosh's house, in south edge of the northwest quarter of section 8, Sheldon, has its crest 1,083 to 1,084 feet above the sea. His well, near the top of the beach, 22 feet deep, is soil and sandy clay to a depth of 7 feet, then sand 15 feet to water. Till rises to the surface 20 rods farther west. About 30 rods east, on land 10 feet lower, a well 10 feet deep is all caving sand below the black soil, which is 1 or 2 feet deep.
Maple River in section 32, Highland, about 2 miles northeast from its most southern bend, 1,019 feet. It is 20 to 40 feet wide and 1 to 3 feet deep, with cobbles and bowlders in many portions of its channel. Herman beach, a sand and gravel deposit, extending a quarter of a mile from south to north on the verge of the bluff of till west of Maple River in the northwest part of this section 22, 1,072 to 1,077 feet. In the north edge of the northwest quarter of this section, the northeast corner of section 31, and the east edge of section 30, it is a plateau-like tract a fourth of a mile wide, with a subsoil of sand and fine gravel, 1,086 feet, from which both east and [p.318] west a gentle slope falls 5 feet within 20 or 30 rods. In the northwest quarter of section 20 and the west half of section 17, Highland, it is a gracefully rounded ridge, 1,085 to 1,087 feet, with descent of about 5 feet on its west side and 10 to 15 feet within as many rods on the east. The surface east of the Maple River in this township has an elevation of 1,075 to 1,065 feet, declining toward the north and east. In the east half of Pontiac, the next township on the west, a surface of till, moderately undulating near the beach of Lake Agassiz, but prominently rolling at a distance of 3 miles to the west, rises to 1,150 and 1,175 feet in the vicinity of the Maple River above its south bend.
The Herman beach, a broad, flattened ridge of sand and gravel, passes in a north-northeast course through the center of section 8, Highland, its elevation being 1,083 feet. A smoothed surface of till, 1,082 to 1,087 feet, with occasional sloughs in depressions 15 to 20 feet deep, occupies the west half of this section 8; and close east of the beach a flat of till on the east line of the section, at 1,065 to 1,070 feet, was the bed of the lake.
Continuing northeastward, the beach is offset a mile to the east, in sections 4 and 3, Highland, so that the greater part of section 4 was a bay of Lake Agassiz during its Herman stage, with bottom at 1,080 to 1,065 feet, inclosed on the west, north, and east by beach deposits. The highest portion of the hook or spit east of this bay is in the southwest quarter of section 3, 1,093 to 1,096 feet. It is composed of sand and fine gravel, with pebbles mostly less than an inch, but occasionally 2 inches in diameter, forming a smoothly rounded swell 30 to 40 rods wide. This cape, projecting south and west a mile into the lake, was accumulated by the southward drift of the beach material along the shore, caused by northern winds, as is also observable at various other places on both the east and west shores of this glacial lake and on both sides of Lake Michigan at the present time.
Herman beach in the west edge of section 26, Eldred, 1,094 feet. On the east side of the beach here, near the center of this section, is a slough filled with rushes and containing water all the year; its elevation is about 1,065 feet, that of the land on its east side, in the east part of this section, being about 1,075 feet. In the northeast quarter of section 34 the beach is intersected by a sluggish creek, apparently formed by springs within a [p.319] half mile northwest, its ravine being fully 40 feet below the general level of the beach and the land westward. Again, in the southwest quarter of section 26 the beach is cut by a dry channel, the outlet in rainy weather from a small slough.
Through the west half of section 23, Eldred, the beach is a low, smoothly rounded ridge of sand and fine gravel, about half of which is limestone and the rest granite or other Archean rocks. As in the 3 miles next southward, it is largely composed of fine gravel, and pebbles abound, often covering half the surface of the knolls made by gophers. Most of the pebbles are less than an inch in diameter, but some measure 2 and a few 3 inches. The elevation of this beach ridge is 1,092 to 1,100 feet; on the north line of this section its height is 1,099 feet. A broad depression 3 to 5 feet below the beach borders its west side. Toward the east there is a descent of about 10 feet in 25 or 30 rods, and thence a gradual slope sinks to 1,060 or 1,050 feet within 1 to 1½ miles.
Undulating till in sections 22 and 15, Eldred, 1,095 to 1,110 feet; crests of prominently rolling till in the west edge of section 11 and the south part of section 10, 1,115 to 1,125 feet; thence northwestward lower undulating till has an elevation of only 1,090 to 1,100 feet for nearly 2 miles, and rises quite slowly beyond. This somewhat irregular contour has caused considerable diversity in the development of the beach, so that its deposits are massed in unusual amount in some places, while elsewhere they are deficient or wholly wanting. In the southwest quarter of the southwest quarter of section 14, Eldred, a swell of gravel, with pebbles up to 2 inches or rarely 3 inches in diameter, rises to 1,105 feet, extending about 40 rods from south to north; and similar gravel, at 1,095 to 1,105 feet, occurs in the west part of the northwest quarter of section 23, west of the distinct beach ridge. The northwest part of section 14 is a nearly flat tract, having a subsoil of sand and fine gravel, with an elevation of 1,090 to 1,095 feet. A beach ridge extending south from the east side of a prominent swell of till in the southwest quarter of section 11, at 1,086 to 1,089 feet, has a continuous depression of about 5 feet on its west side and is bordered eastward by land 6 to 10 feet below its crest. In the northwest part of this section 11 and the southeast part of section 3 the shore of Lake [p.320] Agassiz is marked by slight erosion in the rolling and undulating surface of till rather than by the usual beach deposits of gravel and sand.
Beyond this, a conspicuous beach ridge 25 to 40 rods wide, elevated 10 feet above the undulating till on its west side and bordered by a still lower surface on the cast, extends from the middle of the southwest quarter of the southeast quarter of section 3, Eldred, northwestward to near the middle of the north line of the northwest quarter of this section, where it is interrupted by a drainage gap about 20 feet below its crest. Thence this massive beach ridge continues in a north-northeast course through section 34, Howes, to near the middle of its north line. Its material is sand and gravel, with pebbles up to 1½ inches in diameter. In section 3 its elevation is 1,095 to 1,090 feet, and in section 34, 1,089 to 1,094 feet. It passes onward as a very distinct and typical beach ridge, with the same north-northeast course, through sections 27 and 22, Howes, having an elevation of 1,087 to 1,095 feet in section 27 and 1,089 to 1,096 feet in section 22. Its eastern slope in these sections descends 15 to 20 feet.
About a half mile west from this great beach ridge the east edge of section 4 has irregular deposits of beach gravel and sand in swells and bars 5 feet above the general level, and in the east edge of section 33, Howes, a well-defined parallel beach begins, having a width of 20 to 25 rods and elevation of 1,092 to 1,094 feet, with a depression 2 to 4 feet lower on the west and descent of about 5 feet on the cast. This western Herman beach extends as a continuous ridge 2 miles to the north-northeast, excepting a gap where it is intersected by a small stream in the northwest quarter of section 27. Its material is sand and gravel, with pebbles up to 2 inches in diameter, about half being limestone. Both this and the east beach have a black soil a foot or more in depth, and are scarcely inferior to the adjoining areas of till in productiveness. Farther west a slightly undulating or nearly flat surface of till extends from a half mile to 1½ miles before it rises above 1,095 feet, and the highest of its swells, seen 3 to 6 miles away to the west and northwest, do not exceed 1,150 or 1,175 feet. The western Herman beach on the north line of the northwest quarter of section 27 has a height of 1,095 feet; about 6 rods to the south, 1,097 feet; and northeastward, [p.321] in section 22, 1,092 to 1,095 feet, to its junction with the eastern or main beach in the east part of this section.
A lower Herman beach, formed after the lake level here had fallen slightly, appears in the northwest edge of section 26, Howes, having its crest at 1,072 to 1,075 feet; passing north-northeastward through the west half of section 23, its elevation is 1,075 to 1,080 feet; through section 14, 1,080 to 1,087 feet, being highest near the center of this section; and in the east part of sections 11 and 2 and onward to the southwest quarter of section 36, Buffalo, 1,083 to 1,080 and 1,075 feet. Its maximum development is in section 14, where it is a massive, smoothly rounded ridge of sand and fine gravel, 30 rods wide, with a descent of 15 feet on each side. In sections 26 and 23 it is bordered on the west by a continuous depression 4 to 8 feet below it; and through sections 14, 11, and 2, and in the southwest quarter of section 36, a slough 3½ miles long, mown for its luxuriant marsh bay, having an elevation of 1,067 to 1,072 feet, lies between this and the main beach, a half mile farther west.
Floor of S. P. Gardner's house, in the northwest corner of section 27, Howes, 1,096 feet.
Main Herman beach through the west edge of section 14, Howes, 1,096 to 1,093 feet, declining northward; in the west part of section 11, 1,093 to 1,095 feet; in section 2, 1,092 to 1,095 feet, changing from a north to a north-northeast course; in the southeast edge of section 35 and the northwest edge of section 36, Buffalo, 1,092 to 1,096 feet; and in the west part of section 25, where it is cut by the Northern Pacific Railroad, 1,095 to 1,101 feet. At the railroad cut its crest is 1,099 to 1,101 feet, and the track is 1,092 feet above the sea. Along this distance of 5 miles it is a typical beach ridge of sand and gravel, with pebbles up to 2 inches and occasionally 3 to 6 inches in diameter, about 30 rods wide, rising nearly 25 feet above the slough on the east, and bordered on the west by a continuous depression, mostly about an eighth of a mile wide, 3 to 7 feet below its crest. Slightly undulating till rises beyond to 1,125 and 1,140 feet within 1 or 1½ miles west, which is as far as the surface lies within view.
Northern Pacific Railroad track at Wheatland, 993 feet; on bridge over creek in the east edge of section 25, Buffalo, 4 miles west of Wheatland [p.322] and three-fifths of a mile east of the Herman beach, 1,076 feet; bed of the creek, 1,057 feet; track at summit, 4½ miles west from the Herman beach, same as the natural surface, 1,208 feet; and at Buffalo, a half mile farther west, 1,202 feet.
(PLATE XXVIII.)
The Herman beach, a broad, smoothly rounded, continuous ridge of the same material and contour as southward, runs to the north-northeast for the next 4 miles north from the Northern Pacific Railroad, with its crest at 1,097 to 1,100 feet, very constant in elevation. The descent of its east slope is 15 or 20 feet in about 20 rods, and of its west slope about 5 feet. Thence westward the surface is undulating till, in swells 10 to 15 feet above the depressions, rising gradually to 1,150 and 1,200 feet above the sea at a distance of 3 to 5 miles, the farthest seen in that direction. In a broad view this area seems an almost flat plain.
Where this beach is cut by the branch of the Great Northern Railway from Ripon to Hope, near the middle of the line between sections 32 and 33, Empire, its crest was 1,096 to 1,099 feet above the sea. It has been excavated here for ballast to a distance of about 30 rods south from the railway. It is mostly gravel; the pebbles seldom exceed 2 inches in diameter; about half is limestone, and the remainder granitic. The thickness of this beach deposit is only 8 to 10 feet; its east slope falls 12 or 15 feet, and its west slope 5 to 7 feet.
On the floor of this excavation, about 10 rods south from the railway, in the upper foot of the till or bowlder-clay, under the gravel, numerous bones of a mammoth were found in the year 1884. These included a tusk 11 feet long and 9 inches in diameter (tapering to 6 inches at the smaller end, where it was broken off), three teeth, two vertebrae, and several other bones. They were embedded in the top of the till, and the overlying beach formation has yielded no bones, shells, or other fossils.
Southward from this locality the Herman beach is double for a distance of about 4 miles. The secondary beach ridge east of that already described is similar in size and material. Its south end is in the west part [p.323] of section 19, Wheatland, a half mile east from the main beach, and it passes thence north-northeastward through sections 18, 7, and the east edge of section 6, having an elevation of 1,081 to 1,084 feet. It becomes merged with the main beach in the southeast quarter of section 32, Empire. Between these beach ridges is a depression, approximately 1,075 feet, partly occupied by a grassy slough, which is all used as mowing land, having no area of water or bog.
The Herman beach in the southwest quarter of section 28, Empire, at a height of 1,094 to 1,096 feet, is not so distinct as usual, being intersected by Swan Creek and having no well-marked depression along its west side. Farther north in this section it is a ridge of the ordinary type, with its crest at 1,096 to 1,098 feet. In section 21 it is narrowed to 8 or 10 rods in width, but continues as a very distinct ridge with a slight ascent northward, from 1,097 to 1,101 feet. Its east slope falls 15 to 20 feet in about 20 rods, and there is a depression of 3 to 6 feet on the west. Thence a surface of undulating till, seeming nearly flat in a general view, rises gradually westward to about 1,150 feet at a distance of 2 or 3 miles.
This beach ridge passes onward through section 16 and the south part of section 9, Empire, with an elevation of 1,095 to 1,100 feet; but, having been followed thus continuously in a north-northeast course for more than 15 miles, it ceases in the east part of this section 9. Its north end abuts at 1,100 to 1,105 feet upon a terrace slope of till, which rises about 10 feet higher. This forms the east boundary of a slightly undulating expanse of till, which thence gradually rises to 1,150 and 1,200 feet in 2 to 5 miles west and northwest. From section 9 northward through the east part of section 4, and in the west edge of section 34 and the west part of sections 27) 22, and 15, Erie, passing close east of Erie railway station, the Herman shore of Lake Agassiz is marked by such a terrace or escarpment formed by wave erosion, and the usual deposit of beach gravel and sand is absent. The base of the escarpment is at 1,095 feet, approximately, and it rises with a moderate slope 25 to 40 feet.
About a half mile east of this escarpment, however, lies a broad, low ridge of beach sand and fine gravel, having an elevation of 1,085 to 1,090 feet. Its course is from the west part of section 10 north-northeast through [p.324] sections 3 and 34, and nearly due north through the east edge of sections 27, 22, and 15. The descent eastward is more gentle than usual, falling only 6 to 10 feet in a quarter of a mile, beyond which is a flat area of till. On the west a depression 3 to 5 feet deep, partly occupied by a grassy slough, intervenes between this beach ridge and the wave-cut escarpment. On the north line of section 15 the crest of the ridge is at 1,092 feet; the depression west, 1,088; the base of the escarpment, 1,092, and its top, about 1,115 feet.
Great Northern Railway from Ripon to Portland, track at tank and section house close south of Rush River, 1,094 feet; at Erie, 2 miles farther north, 1,126 feet; summit about 1 mile north of Erie, 1,131 feet; South Branch of the North Fork of Elm River, bridge, 1,081 feet; bed of creek, 1,062 feet; track at summit 1 mile north, 1,089 feet; at Galesburg, 1,079 feet; North Branch of the North Fork of Elm River, bridge, 1,076 feet; bed of creek, 1,063 feet; track at Clifford, 1,055 feet. At Erie and westward the surface is prominently rolling till, which rises within 3 miles to a height of 100 feet above the shore of Lake Agassiz.
In sections 10 and 3, Erie, the Herman beach is again well exhibited in its usual character. On the north line of section 10 it is a gently rounded ridge of sand and gravel, with pebbles up to 2 inches and rarely 3 or 4 inches in diameter, half being limestone; its width is about 20 rods; the elevation of its crest is 1,106 feet, and the slopes fall 10 feet on the east and 3 feet on the west. For the next mile northward, through the west part of section 3, this beach ridge has a width of 10 to 15 rods; its elevation is mostly 1,105 to 1,108 feet, with a depression 5 to 7 feet deep along its west side; but in a few places the ridge itself is depressed to 1,099 feet. Passing northward, this beach in the west half of section 34, Dows, is a very smooth, gracefully rounded, wave-like swell, 30 to 40 rods wide, 1,108 to 1,112 feet in elevation, rising 15 feet above its east base and having a depression of 3 to 5 feet on the west. A well in the northeast quarter of the southwest quarter of section 34, on the top of this beach, went through 12 feet of sand and gravel, going into till below. In the southwest quarter of section 27 the beach continues with the same massive development and nearly north course, its elevation being 1,111 to 1,115 [p.325] feet. In the northwest quarter of this section it becomes a still broader deposit of gravel and sand, a fourth to a third of a mile wide, with no depression on its west side. Here its course is turned northwestward, entering the southeast quarter of section 21 with an elevation of 1,109 feet; but it seems not to be distinctly traceable farther. About a half mile west of this beach a plateau of till, 1,125 to 1,128 feet above the sea, extends a third of a mile from southeast to northwest in the southeast quarter of section 28; but for a mile south and west of this plateau, and for 3 miles northwest, the surface of slightly undulating till averages only 1,105 to 1,120 feet.
The secondary Herman beach, already described in its course east of the Erie escarpment of till, continues northward with an elevation of 1,095 feet, approximately, through the east half of sections 10 and 3, Erie, and sections 34 and 27, Dows. In sections 22 and 16 this beach turns in a gradual curve to the northwest and west, and its crest varies in height from 1,095 to 1,104 feet, being highest in or near the southeast corner of section 16. There it is a ridge of gravel and sand about 30 rods wide, rising 10 to 15 feet above its northeastern base and descending 6 to 10 feet on the southwest to a nearly flat tract of moist mowing land fully a mile wide, with a height of 1,090 to 1,095 feet. Through sections 17, 8, and 5 it again curves to the northwest, north, and north-northeast, having an elevation of about 1,095 feet. In the north half of sections 5 and 4, Dows, a smooth plain with sand subsoil extends a mile eastward from the east base of this beach ridge, descending in this distance from 1,090 to 1,075 feet.
Continuation of this beach northward nearly through the middle of section 32, Galesburg, 1,096 to 1,099 feet. It is ca typical beach ridge of fine gravel and sand, 8 to 10 feet above the land on its east side and having a descent of about 5 feet westward, beyond which the surface of undulating till rises in 1 or 1½ miles to 1,125 feet and in the next 2 miles to 1,175 or 1,200 feet. A half mile east from this beach, and only 20 to 30 rods west of the railroad, there is a parallel beach ridge of similar size and material, at 1,090 to 1,092 feet. The former of these beaches, where it crosses the south line of section 20, a fourth to a half mile west of Galesburg, is spread in a broad, nearly flat deposit which rises westward from 1,096 to 1,101 feet. On the west it is bordered by a depression about 8 feet lower.
In section 20, Galesburg, the beach is about a third of a mile wide, its higher western margin being at 1,097 to 1,102 feet. From its crest a slope descends first somewhat steeply and then slowly to the amount of 20 or 25 feet in two-thirds of a mile eastward, having a subsoil of sand and very fine gravel to a depth of 5 to 10 feet, underlain by till, as is shown by wells at Galesburg. Crest of this beach through the west half of section 17, 1,102 to 1,107 feet; in section 6, Galesburg, and in sections 32 and 29, Norman, 1,115 to 1,125 feet, being 10 to 15 feet higher than on the south and north; in sections 20 and 17, about 1,110 feet; in the southwest part of section 8, 1,117 feet westward through section 7 of this township, and through the northeast part of section 12, township 145, range 54, 1,112 to 1,117 feet. On the line between Traill and Steele counties, where the top of the ridge is at 1,114 feet, it is a typical beach deposit about 25 rods wide, composed of sand and gravel, with pebbles up to 2 or 3 inches in diameter, Its course is due west, and the descent from crest to base on the south is 6 or 8 feet, and northward 12 or 15 feet, beyond which a very gentle slope sinks toward the northeast. A well on this beach, in the east edge of the northwest quarter of section 12, township 145, range 54, went through sand and fine gravel 13 feet, finding till below. Within a few hundred feet farther west the beach is interrupted for a distance of about 1 mile by an area of till some 15 feet lower, with no beach deposits. It reappears, however, as a typical beach ridge of gravel and sand for a distance of three-fourths of a mile in the northwest quarter of section 11 and the northeast quarter of section 10, having an elevation of 1,114 to 1,112 feet, with a slough on its south side 6 to 8 feet lower.
Returning to the vicinity of Galesburg, a slightly higher beach, approximately parallel with the foregoing, remains to be traced. It becomes recognizable in the west edge of section 20, Galesburg, where the border of the area of rolling till that extends thence westward bears occasional deposits of gravel at 1,115 to 1,120 feet. In the east part of section 18 it is a well-developed beach ridge of sand and fine gravel 30 to 50 rods wide, [p.327] with a depression on the west 4 to 6 feet below its top, which has an elevation of 1,120 to 1,123 feet. Northward in section 7, this beach, continuing at 1,120 to 1,123 feet, is quite broad, without a distinctly ridged form, and is indented from the east by a large slough, whose elevation is approximately 1,100 feet, including several acres of water free from grass and rushes.