The Survey 



Ue Imaha River e — (Not sijrveyed,) The Imnaha River joins the 

 Snake River approximately 190 miles above the Columbia River conflu- 

 ence. Its drainage area comprises more thsin 900 square miles of 

 northeastern Oregon in the Wallowa National Forest, and includes the 

 eastern slope of the Wallowa Mountains. The stream is about 75 miles 

 longo Gaging-station records for the water-year I9UO-I1I (U.S,G,S,, 

 I9U2) give the mean discharge as 5U8 c.f.So at Imnaha, 20 miles above 

 the mouth. The stream flows through an extremely rugged, mountainous 

 area, and has not been subjected to demands for water use by any agri- 

 cultural or industrial development. The gradient is fairly steep 

 throughout. Imnaha Falls is located about 65 miles above the mouth. 

 This falls was reported to be a barrier to salmon. The Imnaha formerly 

 supported good runs of chinook salmon and steelhead trout, but the 

 present runs were reported to be very small. 



$• Pine Greek , — (July 1?, 19U2} Parkhurst.) Pine Creek joins 

 the Snake River at Copperfield, Oregon, approximately 269 miles above 

 the Columbia River confluence , Its drainage area comprises more than 

 300 square miles, and includes a portion of the southeastern slope of 

 the Wallowa Mountains, The main stream is about 32 miles long. The 

 greater part of its course lies adjacent to the southern boundary of 

 the Minam Division of the Whitman National Forest, It was reported 

 that no salmon have been seen in Pine Greek for about the past 15 years, 

 A small winter and early spring run of steelhead trout still ascend 

 to the upper part of the stream, and also enter a number of tributaries. 

 he survival of the steelhead rvin has been possible because these fish 

 ent^r during highwater periods, and are not subjected to adverse water 

 conditions. Topographically the Pine Creek drainage basin may be divided 

 into four sections; (l) Lower Pine Canyon; (2) Pine Valley; (3) Carson 

 to Cornucopia, Oregon; and (Ii) Cornucopia to the headwaters. 



Section (1) - Lower Pine Canyon t 



Pine Creek extends through a narrow, rocky canyon from the 

 mouth to a point about 12 miles upstream. The stream was U5 feet wide 

 at the mouth, and was dischsirging about 90 c.f .s. The water tempera- 

 ture was 70,0 F, at the mouth. The gradient is fairly steep to moder- 

 ate in this section, and there are numerous good shallow riffles and 

 adequate resting pools. It was estimated that about 50 percent of the 

 stream bed constituted suitable spawning area. However, the high water 

 temperatures occunrLng in the late summer months would be an adverse 

 factor to spawning salmon. 



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