the mouthy discharg^ing over 200 CofnS., and is fed by glaciers on 

 South Sister Mountain. The stream is in a narrow valley in rugged, 

 forested^ mountainous country, and has a fairly steep gradient. The 

 stream is almost a continuous series of cascades and lo?; falls . 

 Spawning riffles and resting pools are scarce. A log jam and a 

 series of low falls at the upper end of t"he survey is believed to 

 be impassable. It could support only a feyi salmon. Tvro tributaries. 

 Rainbow Creek , flowing 5 c.f.Sc, and Louise Creek , 40 c.f.s., each 

 having impassable falls near their mouths, 



25DI>-(18), Lost Creek .— (August 20, 1937, Baltzo.) Enters the 

 McKenzie River 1 mile below Belknap Springs, or 70 miles above the 

 mouth. The stream is nearly 4- miles long. This stream is unusual in- 

 asmuch as it has a tributary much larger than itself c It rises in a 

 large spring, 2 acres in extent, at the food of an enormous lava flow 

 in a 1/2 mile vfide wooded^ flat valley floor. Numerous smaller springs 

 contribute to the flow. The vraters of these springs are very clear, as 

 is the 3/4 mile of stream from the source down to the confluence with 

 the 7/hite Branch. From this point to the nouth the water is always 

 milky ivith glacial silt, and only in cold vieather is the stream bed 

 visible o Silt is also thickly deposited between large blocks of broken 

 lava in the lo7/er section of the course. 



The average stream v/idth. v;as 45 feet, the discharge vras 231 c»f .s., 

 and the spring flow above the Wiite Branch was 152 c.f .s., and is fair- 

 ly constant. The spring water temperature was 442'°F» The springs and 

 valley floor are choked with a dense gvovrth of underbrush, ferns, and 

 grasses o The current is uniformly deep and sv/ift throughout the entire 

 course, v;-ith pools occurring only in the form of small pockets and ed- 

 dies along the banks© In spite of the silting and broken lava, there 

 are occasional patches of ideal spavming area, amounting to about 5 per- 

 cent of the bottom, capable of supporting several hundred spa-vming 

 salmon. 



Old time residents reported that there vfere i'orraerly heavy runs of 

 spring Chinook in Lost Creek in late August, and a fev; that escai^e the 

 McKenzie River racks sti].l spavm there every year. One redd and a spent 

 male were observed by the survey party. Other salmon vrere probably 

 present, but were not seen because of unfavorable observation conditions. 

 Small rainbov/ trout were numerous in the creek and springs. 



25DD-(lQ)a. Wliite Branch o — (August 20, 1937; Kolloen.) Enters Lost 

 Creek 3 miles above the mouth, and extends for about 15 miles, of Tirhich 

 the lower 4 miles were surveyed up to a series of falls 60 feet high. 

 The stream rises at Collins Glacier on Three Sisters Mountain, and is 

 heavily charged vd.th glacial silt. The bottom for the most part is com- 

 posed of porous lava rock, wtiich causes a large part of the flow to be 

 underground at many places. The discharge viras 79 c.f.s., at the mouth, 



67 



