20 



ing hills until it reaches Sevenmile Canyon. The walls of this cari- 

 yon rise almost perpendicularly to a height of about 2,000 feet above 

 the river bed. Beyond Sevenmile Canyon the river flows through 

 another stretch of hilly country, then enters the Alcova Canyon. 

 From Alcova to Casper the river is bordered by a high, level plateau. 

 Between Alcova and Casper, Bates Creek, Poison Spider Creek, and 

 Casper Creek enter the North Platte. These streams are not per- 

 ennial, but are used for irrigation in the spring. There is almost no 

 irrigation from the North Platte between Fort Steele and Casper, and 

 little land which can be irrigated. Narrow strips of bottom lands 

 along the tributaries are, however, irrigated, and this area is being 

 constantly extended. From Casper to Orin the river flows in a wide 

 valley, winding back and forth across this valley in a sandy bed. In 

 times of low water it is divided into several channels. 



Surveys have been made for a number of canals to cover parts of 

 this valley, but only one has been completed, and it is now out of 

 repair. This section, however, affords some of the best examples of 

 irrigation in the Platte Valley. Many ditches divert the waters of the 

 tributaries of the Platte, reservoirs have been built, and the complete 

 utilization of the water supply in the near future is assured. In this 

 section, between Casper and Orin, Big Meadow, Deer, Box Elder, La 

 Prelle, Wagon Hound, and La Bonte creeks enter the river. These 

 streams are all used for irrigation, and supply very little water to the 

 main stream. Below Orin on each side of the river for a distance of 

 5 or 6 miles there is considerable irrigated land, which is watered by 

 three ditches, the largest of these being about 10 feet on the bottom 

 and 2 feet deep. Ten miles below Orin the river enters broken coun- 

 try, with occasional stretches of land which could be reclaimed by 

 lifting water from the river. The valley broadens again at Guernsey, 

 this valley extending to and beyond the State line. Several good- 

 sized ditches take water from the river in this section and irrigate 

 considerable areas of land. Other canals which are under construc- 

 tion will irrigate between 25,000 and .50,000 acres. Elkhorn, Horse- 

 shoe, Cottonwood, and Eawhide creeks and the Laramie River enter 

 the river in this section. 



LARAMIE RIVER. 



The Laramie River rises in northern Colorado in the vicinity of 

 the other streams which go to form the North Platte and flows 

 through Wyoming in a course generally parallel to the North Platte, 

 the two coming together near the Wyoming-Nebraska line. There is 

 little irrigation along the Laramie in Colorado ; some of its water is, 

 however, carried over the divide separating its headquarters from 

 those of the Cache la Poudre, and is used in the valley of the latter 



