Glaciers, which at one time covered virtually the 

 entire region, left many moraines— heaps o£ bould- 

 ers, gravel, sands, silt, and clay— with hundreds of 

 small lakes scattered throughout. These are most 

 noticeable across central Minnesota, Wisconsin, and 

 the Lower Peninsula of Michigan (fig. 1). The 

 smoother parts with heavier soils are farmed. The 

 steeper and stonier parts, being of little use for farm- 

 ing, have remained in forests as have also many of 

 the intermingled pot holes and poorly drained de- 

 jiressions. Some of the best red and white pine 

 "xew on these moraines. 



lent white pine in the original forest; but its second 

 growth is mainly aspen of intermediate quality with 

 little evidence of any tendency to revert to pine. 

 Receding glaciers left several sizable lakes, includ- 

 ing Lake Agassiz, which covered northwestern Min- 

 nesota and thousands of square miles in North 

 Dakota and adjacent parts of Canada. Lake Winni- 

 peg, Rainy Lake, and Red Lake are remnants. The 

 former bed of Lake Agassiz and similar smaller lakes 

 now contain extensive tracts of peat of varying 

 depths, with scattered dunes or "islands" of sand. 

 The characteristic vegetation is spruce, tamarack, 



EEij GLACIAL MORAINES 



I 1 FORMER LAKE SHORE 



IZH ROCK OUTCROP 



I'H.UKi: l.—Sigiiilicdiil i()li<>gui[>liic jciiliiic^ uj the Lalic Sliihs icgiu)}. 



Glacial till plains generally are of better texture 

 and less broken profile. Usually they are fertile 

 and, in districts of favorable climate, make s<ood 

 farm land. 



Glacial oiUwash plains are mostly coarse sand, not 

 highly valued for agricultural development. In the 

 north, they produce jack or red pine; in the south, 

 scrub oak. 



.\ narrow band of heavy clay soils adjoining the 

 Great Lakes occupies area formerly covered with 

 water. This is fertile soil and in the soiuh it makes 

 good farm land. In the far north, it tends to be 

 cold, poorly drained, and intractable. Some of this 

 land, as for example near Duluth, produced excel- 



2 Forest Resour 



and cedar trees, or some of the \ arious rushes, sedges, 

 and shrub species adapted to wet ground. Pine 

 trees grow on many of the islands. 



The bluff lands on both sides of the Mississippi 

 River from St. Paid south to the regional boundary 

 at Duljucjue, Iowa, present a particularly severe 

 erosion problem. This l(),()0()-st}uare-mile area ' 

 contriijutes millions of tons of silt to tlie Mississippi 

 annually, and tliousands of acres of good farm land 

 have been gullied beyond repair. Erosion has re- 

 sulted in part from cropping or pasturing steep land 

 that never shoidd have been cleared, and in part 

 from using improper cropping methods on good 

 agricultural land. In recent years progress has been 



ce Report No. 1, U. S. Department of A<j^rintlture 



