From the mouth to Mesa Dam there were 5,200 square yards 

 of suitable spawning area, constituting approximately 5 percent of 

 the total bottom in that area. Spawning below the Mesa DsP would 

 probably be unsuccessful because of seasonal low flows and hi^ 

 water temperatures. Frcra Mesa Dam to an impassable falls there 

 were 1,800 square yards of suitable spawning area, constituting 

 approximately 3 percent of the total bottom in that area, and avail- 

 able only at high water. 



There were 8 irrigation diversions on the stream, the most 

 important being the Mesa ditch, located about 8 miles above the 

 mouth o This diversion has a legal right to all the water in the 

 stream during the iiTigation season* It is also the source of 

 domestic water supply for the town of Mesa* On the date of obser- 

 vation the Mesa ditch was withdrawing U8 Cof .s* It was reported 

 that the stream bed is often practically dry below the diversion point 

 during part of July, August, and September, The diversion dam is a 

 wooden structure extending 32 feet downstream in a series of three 

 low, broad steps© It is a barrier to fish at low water* 



■^here is a falls 2$ feet in height located about 13 miles 

 above the mouth. It is a total barrier to fish. 



Good runs of Chinook salmon and steelhead formerly enter- 

 ed the Middle Fork, The stream is of no present /St potential value 

 to migratory fish because of the extensive withdrawal of water for 

 agirLcultural and domestic use, 



2P-(1). Fall Creek .— (August 21, 19Ulj Frey and Bryant.) Fall 

 Creek enters the Middle Fork of the Weiser River approximately 7 

 miles above the mouth. The stream is about 6 miles long, and has two 

 important irrigation diversions. All the water from the upper part of 

 the stream is diverted into the North Fork of Grays Creek, a tributary 

 of the Little Weiser River, and is used to irrigate land in the vici- 

 nity of Indian Valley, Two miles above the mouth another diversion carries 

 the remainder of the stream into the Mesa Ditch* Fall Greek is of no 

 present or potential value to salmon because of its extensive agricul- 

 tural iise. 



2Q, Cottonwood C reek ,— ^ (Not surveyed,) Cottonwood Creek enters 

 the Weiser River approximately ^2 miles above the mouth. The stream 

 is about 11 miles long. There were six irrigation diversions on the 

 main stream and one on 2Q-(l) North Cottbnwood Creek. There were no 

 reports of salmon entering the stream in recent years. Because of 

 the extensive withdrawal of water for irrigation and the hazards to 

 fish presented by the unscreened diversions, Cottonwood Creek was consid- 

 ered of no value to salmon and of only slight value to steelhead. 



2R. Hornet Creek , — (August 16, 19LJ.; Frey and Bryant.) Hornet 

 Creek enters the Weiser River approximately $k^ miles above the mouth. 

 The main stream is about 18 miles long, Gsiging-station records for 



ho 



