1 . STREAM 

 Sevenmile Creek 



2. DESCRIPTION 



Sevenmile Creek originates on the east slope of the Anaconda-Pintlar 

 Range at the Continental Divde and flows in a southerly direction for about 

 5.6 miles to its juncture with Tenmile Creek to form Deep Creek. The 

 stream drops rapidly through a narrow, steep -sided canyon in the upper 

 reaches and meanders through grasslands and willow bottoms in the lower 

 reaches. The 5 square mile drainage area is characterized by open south facing 

 slopes and timbered conferous ridges. Streamside vegetation is typically 

 riparian in nature and composed primarily of willow, alder, grasses and sedges. 

 Numberous beaver ponds are found in the lower reaches of the stream. Seven- 

 mile Creek has no major tributaries. The average gradient of the 6.1 foot 

 wide channel is 37.2 feet per mile. Ownership of the Sevenmile Creek drainage 

 is controlled mainly by the MDFWP while a small portion of the drainage is under 

 USPS control. 



Lands within the Sevenmile Creek drainage are used for recreational pur- 

 poses; primarily hunting, fishing and snowmobil ing. No estimate of fishing 

 pressure is available for Sevenmile Creek; however, some fishermen were 

 observed during the summer of 1980. Past commercial uses of the drainage 

 include livestock grazing, timber harvest and numerous diversion of water for 

 agriculture, mining and timber harvest. Present commercial uses include 

 livestock grazing and possible timber harvest. 



Chemical analyses were performed on water samples collected during the 

 summer of 1980. The data revealed that Sevenmile Creek is a calcium- 

 magnesium-bicarbonate water of slightly basic pH. Specific conductance, 

 total alkalinity, hardness and nitrate concentrations were much higher than 

 values measured from other Mount Haggin streams, resulting in a chemically 

 rich water of good quality. Environmental concerns include streambank in- 

 stability and erosion in the lower reaches of the stream resulting from 

 vehicular travel and livestock use. 



3. FISH POPULATIONS 



A 1,000 foot section of Sevenmile Creek was electrof ished on August 12 

 and August 21, 1980. Game fish captured in descending order of abundance 

 were brook trout, rainbow trout and rainbow-cutthroat hybrid trout. Nongame 

 species present were mottled sculpin and longnose suckers. Electrofishing 

 survey data are presented in Table 16. 



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