584 THE GLACIAL LAKE AGASSIZ. 



pasturage. The smooth, gently undulating or nearly flat areas of till, 

 which are far more extensive than the morainic belts, can be plowed often 

 across a distance of several miles, bounded only by stream courses, with- 

 out enco^^ntering a bowlder or tree or bush to require the plow to deviate 

 from its straight and continuous furrow. The few bowlders which are 

 found on these lands, seldom exceeding 3 to 5 feet in diameter and varying 

 in numbers from perhaps one to five or ten per acre, are scarcely so many 

 as the farmer desires for the construction of cellar walls, foundations of 

 buildings, and for other uses. 



Large portions of the deltas of Lake Agassiz, and the whole of the 

 broad, flat expanses of lacustrine and alluvial silt which adjoin the Red 

 River, have no bowlders nor gravel. Here the ideal conditions are found 

 for the cultivation of single fields of grain occupying hundreds or thou- 

 sands of acres. Though the subsoil of many arable tracts of the Red 

 River Valley is saturated with moisture throughout the year at the depth 

 of only a few feet below the surface, even these moist areas have sufficient 

 slopes to drain away the water of snow-melting and the rains of spring in 

 season for early sowing. While the soil of both the till and the lacustrine 

 and alhndal deposits is prevailingly clayey, it yet is nearly everywhere 

 sufficiently sandy and porous to permit a part of these waters and a large 

 proportion of the summer rains to be absorbed by it. Whenever a tem- 

 porary drought comes, the water thus received and stored at a moderate 

 depth in the subsoil is raised by capillary attraction to the surface. The 

 roots of vegetation are thus nourished, and the growth of the crops is con- 

 tinued Avithout check or a bountiful harvest is often matured without the 

 aid of rainfall during a month or more. 



Some tracts of the Red River Valley are marsh, owing to the flatness 

 of the land and the depression of these tracts a few feet below their natural 

 avenues of drainage. The marshes vary in extent from patches of a few 

 hundred acres up to 50 square miles. 



An enumeration of the most noteworthy of these boggy, partially 

 inundated areas in Minnesota includes the marsh, 6 miles in diameter, occu- 

 pying the greater part of Winchester, Norman County, in crossing which 

 the south branch of the Wild Rice River becomes diftused and lost, until it 



