Upham.] 
234 
[Feb. 18 , 
north of St. Paul ; the Lake of the Isles, and Lakes Calhoun and 
Harriet, in Minneapolis, lying in a series along the preglacial 
course of the Mississippi river ; Sandy lake, the Twin lakes, and 
Palmer lake, on the modified drift bordering the Mississippi within 
a few miles north of Minneapolis ; many lakes in Anoka, Isanti, 
and Sherburne counties, which are mostly overspread with gravel 
and sand beds of glacial origin, having flat, undulating, and rolling 
or kame-like contour ; and probably 200 or 300 of the 1,029 lakes 
which are delineated on the government survey plats of Otter 
Tail county, called by Rev. C. M. Terry “the banner county of 
the state for lakes.” Of the 10,000 lakes, or more, in Min- 
nesota, perhaps 2,500 occur on areas of modified drift. Red 
lake, the largest wholly within the state, and the southwest part 
of the Lake of the Woods, are mostly bounded by such areas. 
Otter Tail lake, West Battle lake, and Lake Clitherall, situated 
near together in Otter Tail county, may be selected as typical, 
having respectively lengths of nine, six, and four miles, and 
widths about a third as great, with maximum depths respectively 
of about 60, 50, and 44 feet. The surrounding deposits of gravel 
and sand range in height from 10 or 20 feet to the Nidaros plain 
100 to 125 feet above these lakes, which are respectively about 
1,315, 1,328, and 1,332 feet above the sea. While the adjacent 
stratified drift was being laid down, these basins were doubtless 
filled with melting remnants of the waning ice-sheet. 1 
Let us endeavor to restore in a mental picture the unique con- 
ditions of the Glacial and Champlain epochs, covering the land 
with ice and anon melting it away, in order to discern how the 
ice-masses filling basins of the modified drift were left standing 
out in peninsulas beyond the general ice-margin or were severed 
from it as islands. Every hill and mountain of Connecticut, 
Rhode Island, Massachusetts, Vermont, and New Hampshire 
was enveloped in the ice-sheet, whose smooth, slightly undulating 
surface stretched as a vast merde glace from Nantucket, Martha’s 
Vineyard, and Long Island northward to the Arctic ocean, and 
from Newfoundland and the Fishing Banks west to the Lauren- 
tian lakes, the great lakes of Manitoba and the Mackenzie, the 
Rocky mountains, and the Pacific coast in Alaska, British Colurn- 
1 Geological and Natural History Survey of Minnesota, Final Report, vol. i, 1884; 
vol. ii, 1888. 
