WilloT/ Creek Reservoir is a 1,400-acre impoundment (fig. 3) on the 

 plains near Augusta, about 15 miles southeast of Gibson Reservoir and 

 about 1 mile off the graded road between Augusta and Diversion Reservoir, 

 Water stored in this reservoir is released, as needed, to satisfy down- 

 stream water rights of 300 second-feet for irrigation. Water enters the 

 reservoir from Willow Creek and Willow Creek Feeder Canal, which stems 

 from Pishkun Canal a short distance belov; Diversion Dam, Willow Creek 

 Feeder Canal has a maximum capacity of 500 second -feet and is 7,5 miles 

 long. 



Tunnel Lake, adjacent to Pishkun Canal, about 6 miles from Pishkun 

 Reservoir, is a former pothole. It novr has a surface area of about 30 

 acres and a maximum depth of about 20 feet. Natural runoff into Tunnel 

 Lake is now intercepted by Pishkun Canal, but this is more than replaced 

 by seepage from the canal. The vrater level rose about 4 feet between 

 May and September in 1951, 



The chain of ponds knovm as Split Rock Lakes also is near Pishkun 

 Canal, about 2 miles above Pishkun Reservoir, Of the many ponds, v/hich 

 are from 3 to 30 acres in size, only 3 or 4 of the largest are fished 

 to any extent. Before the construction of Pishkun Canal, the Split Rock 

 Lakes were shallow potlioles with an undependable water supply; seepage 

 from the canal now supplements the normal inflow and assures relatively 

 stable water levels. 



There are a few other small lakes in the watershed which provide 

 fishing. Wood Lake, 2 20-acre lake near Bench I.Iark, is the most important 

 of these. Actually, Wood Lake is on a tributary of the South Fork of the 

 North Fork Sun River, A short creel census was made at Wood Lake during 

 the course of the study. Other lakes in the watershed v/ere censused but, 

 because of limited use, data were included with that for adjacent streams© 



Augusta, at the lower extremity of the study area, is the closest toivn 

 to the study area (see map), Augusta has a population of about 500 people 

 and is a trading point for the local ranchers, Choteau, 26 miles to the 

 north of Pishlcun Reservoir, has a population of 1,S15, and Great Falls, 60 

 miles directly east of the study area, has a population of 39,214 (1950 

 census). 



The general area is accessible by State Highway 33 which links Augusta 

 T/ith Helena (75 miles to the south) and Choteau to the north, and by State 

 Highway 20 which connects Augusta ^vith Great Falls, A branch line of the 

 Great Northern Railway terminates at Augusta, 



