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THE IRRIGATION AGE. 



IRRIGATION POSSIBILITIES OF 

 WESTERN SOUTH DAKOTA* 



By SAMUEL H. LEA, State Inspector 



In considering the possibilities of agricultural 

 development in western South Dakota one can not 

 fail to be impressed with the vastness of the field 

 and the splendid opportunities for the application of 

 scientific methods. That portion of South Dakota 

 west of the Missouri River comprises a total area 

 of 42,219 square miles or 27,020,160 acres. About 

 56 per cent of this area, or approximately 15,000,000 

 acres, comprises land whose surface is level to roll- 

 ing and will permit the use of farm machinery with 

 little difficulty. These figures are taken from Re- 

 ports of the United States Department of Agricul- 

 ture ; they may be considered fair and conservative. 



On account of the large proportion of the region 

 held as reservations for the Indians, the develop- 

 ment of western South Dakota has been greatly re- 

 tarded. The great Sioux Reservation which ex- 

 tended from the Missouri River westward almost to 

 the Black Hills, and from Nebraska northward into 

 North Dakota, covering nearly one half of the state 

 west of the Missouri; not only precluded any settle- 

 ment in the region actually included within its boun- 

 dary, but also served as a barrier to the development 

 of that part of the state lying west of it. About one- 

 half of this reservation was opened to settlement in 

 February, 1890, and a gateway for the advance of 

 cultivation beyond the Missouri River was thus pro- 

 vided. Other portions have since been opened until 

 now a considerable area is open to settlement. 



In 1907 came the building of the Chicago, Mil- 

 waukee and St. Paul railroads from the Missouri 

 River to Rapid City, as well as the Pacific Coast 

 extension of the latter road through the northern 

 part of the state. These opened up large stretches 

 of country and gave a new impetus to settlement. 

 Land along these lines was rapidly taken up and 

 homeseekers pushed far away from them into the 

 country. Houses sprang up over night and the de- 

 velopment of western South Dakota took on a new 

 meaning. The cattlemen were hemmed in on every 

 side by homesteaders. Towns were laid out which 

 soon grew to be prosperous villages, and today there 

 are many settled communities where comfortable 

 houses, commodious barns, and adequate farm 

 equipment give the best evidence of a permanent 

 population. 



During the first few years the rainfall was above 

 the average and crops were fairly good. Later ex- 

 perience has shown, however, that years of insuffi- 

 cient rainfall must be expected and that irrigation 

 must be provided to insure good crops every year. 

 The necessity for irrigation being recognized it is 

 important to know first the water resources of the 

 region and next the amount of land that can be irri- 

 gated to advantage. 



Water Resources. 



The principal streams in western South Dakota 

 are the Grand, Moreau, Cheyenne, and White Rivers. 



* Address at State Conservation Congress, Pierre, S. D. 



These streams flow through narrow valleys with 

 high, broad terraces, considerably lower than the 

 adjacent country. The flow of water in these 

 streams fluctuates greatly according to the season 

 of the year. Their fall is from an altitude of about 

 3,500 feet along the west end of the state outside of 

 the Black Hills, to the level of the Missouri River, 

 amounting to nearly 2,000 feet. The length of the 

 Cheyenne River within the state is about 500 miles 

 and that of the three other rivers is about 400 miles, 

 consequently their currents are swift and rapids are 

 frequent. The Cheyenne and its northern branch, 

 the Belle Fourche, almost completely surround the 

 Black Hills. Some of the smaller rivers draining a 

 considerable area are the Teton or Bad River, on 

 the divide between the White and the Cheyenne, the 

 Little White River in the Rosebud and Pine Ridge 

 Indian Reservations, the Keya Paha in the Rosebud 



SAMUEL H. LEA. 



Indian Reservation, and the Little Missouri, cutting 

 across a small section in the northwest corner of 

 the state. These streams are dry in places in sum- 

 mer, but at some seasons they carry an immense 

 volume of water. 



Other Streams. 



In the region adjacent to the Black Hills the 

 following streams are capable of being used for irri- 

 gation : Rapid, Sulphur, False Bottom, Bear Btitte, 

 Elk, Alkali, Box Elder, Spring, French, Battle, and 

 Beaver Creeks. These all have a practically continu- 

 ous flow, although, like many other streams in the 

 state, the flow is very small in the dry season. In 

 some cases they pass over limestone strata in some 

 portion of their course and the water sinks under- 

 ground. In flood periods, however, the flow is suffi- 



