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4. Beaverhead River Drainage 



The Beaverhead River drainage (southwest Montana) is defined by the 

 Pioneer Mountains to the west, the Ruby Range to the east, and extends 

 from Clark Canyon Reservoir to the mouth of the Ruby River. The DNR&C 

 basin designation is 41B. All waters are classified as B-Di (DHES) 

 streams except the upper portion of Rattlesnake Creek (A-Open-Dj). 



Forestland ownership in the Beaverhead River drainage is predominantly 

 USPS with additional BLM, state, and private ownerships. In certain 

 areas, intermingled ownership creates an opportunity for uncoordinated 

 management activities which may result in water quality impacts. This 

 situation exists in the Blacktail Deer Creek drainage, where future 

 harvesting is anticipated. 



Timber harvesting has occurred on all ownerships, however, recent activities 

 have been concentrated on small private ownerships. Few impacts to 

 water quality were reported as resulting from forestry activities. The 

 local Conservation Districts (1977) estimated that over 12 percent of 

 commercial forestland within the Beaverhead River drainage (8,000 acres) 

 are contributing to non-point sediment pollution. Approximately 85 

 percent of this acreage was considered to have rehabilitation potential. 

 Many areas within the drainage are characterized by highly erosive 

 soil conditions, due to fine-grained volcanic material and loosely con- 

 solidated sediments. Identified water quality impacts are shown in Table 

 VI-04; locations are shown on Plate I. 



