OVERFLOW OF RED RIVER OF THE KORTH. 5 



The glaciers eroded the hills that then existed and filled the valleys. 

 Eocks were ground into gravel and sand. As the glaciers receded to 

 the north the materials deposited by them were further reduced by 

 waves and currents in the lake. The streams brought down silt which 

 was deposited in the lake. In this manner were formed the topo- 

 graphical features and the soils now found in the watershed of the 

 Red Eiver. 



SOIL. 



The soils throughout the former glacial lake bed are deep, heavy, 

 finely divided, well-compacted mixtures of clay, loam, and small pro- 

 portions of very fine sand. For the first foot or more this mixture is 

 deeply blackened by decayed organic matter. The soils of the valley 

 are classified by the United States Bureau of Soils (Bulletin 96, 1913) 

 as the Fargo series of soils. Six types are mentioned: Clay loam, 

 fine sandy loam, loam, fine sand, clay, and silt loam comprise the prin- 

 cipal areas. In their natural condition most of these soils are poorly 

 drained. All are fertile and, when drained, admirably adapted to 

 agricultural purposes. The soil of the upper levels of the watershed 

 is less uniform in quality and somewhat less productive than that of 

 the central valley, but through drainage, clearing, and proper farm- 

 ing methods practically all can be developed into excellent farm 

 land. Along the edges of the central plain are found moraines and 

 shore lines of the former lake. These are long, low ridges of sand 

 or gravel from a few hundred feet to a half-mile in width. Such 

 land has less agricultural value than any other in the watershed. 



• WATERSHEDS. 



The watersheds of the Red River and its tributaries are shown in 

 figure 1, and their areas are given in Table 1. 



The Red River watershed has been subdivided as indicated on the 

 map and in the table, for the purpose of comparing the precipitation, 

 temperature, topography, soil, vegetation, and natural and artificial 

 drainage of the different portions, as affecting run-off in the valley. 



UTILITY OF THE WATERCOURSES. 



Of the various ways in which the Red River and its tributaries 

 prove useful and valuable to the community the more important are 

 the removal of excess water, water supply, sewage disposal, water 

 power, and recreation. Commercial navigation although in earlier 

 days of great importance has decreased until at present it is insig- 

 nificant. Commercial fishing is carried on to some extent in differ- 

 ent parts of the watershed but the industry is of minor importance 

 in the State boundary waters. Irrigation by water drawn from the 

 streams has been considered, but it has been found that where con- 



