Easy accessibility to the Clark Fork main stem between 

 Missoula and Superior has helped produce the 11th heaviest stream 

 fishing pressure in the state (1985 estimate). However, current 

 MDFUP studies on this 105-mile section have found relatively low 

 numbers of trout for a river of this size. Population estimates 

 indicate an average of 200 to 400 catchable trout (8 inches or 

 larger) in this reach of the Clark Fork. Rainbow trout comprised 

 90 percent of the trout fishery. Preliminary results indicate 

 that a scarcity of high quality trout spawning habitat in the main 

 stem and its tributaries may be limiting catchable trout. 



Historically, the sport fishery of the lower Clark Fork was 

 dependent upon the annual spawning migrations of cutthroat trout, 

 bull trout, lake whitefish and kokanee from Lake Pend Orielle in 

 Idaho. Although the resident fishery of the lower Clark Fork was 

 considered generally "unproductive," this complex of species from 

 Pend Orielle provided a variety of angling opportunities from 

 March to December in the main stem and tributary streams. Access 

 to the lower river by migrating populations was lost when three 

 run-of- the- river dams were constructed beginning in the early 

 1900s. Thompson Falls Dam, 70 miles upstream from Lake Pend 

 Orielle, was constructed in 1916. Noxon Rapids Dam, completed in 

 1959, is located 38 miles downstream from Thompson Falls. Just 

 across the Idaho border, 11 miles upstream from Lake Pend Oreille, 

 lies Cabinet Gorge Dam, completed in 1952. Seventy miles of river 

 habitat has been impounded by these dams, or 34 percent of the 

 river downstream from Missoula. Fisheries mitigation has been 

 provided by the Washington Water Power Co. and numerous fisheries 

 management schemes have been devised, including massive 

 rehabilitation efforts and stocking programs totaling nearly 10 

 million fish in eight species. Target species today include 

 largemouth and smallmouth bass, brown and bull trout, ling and the 

 McCounaghy strain of rainbow trout. 



The range of westslope cutthroat trout historically extended 

 throughout the lower Clark Fork River drainage. Three reaches in 

 the lower Clark Fork rated Class I in the habitat and species 

 value contained isolated pure populations of westslope cutthroat. 

 Lack of genetic verification of the purity of the remaining 

 populations prevent identification of critical habitats. Of the 

 203 miles of stream receiving a Class II habitat and species 

 value, 37 miles in six reaches contained genetically pure 

 cutthroat (tested by electrophoresis) but were threatened by 

 genetic contaminants in the drainage, and another 72 miles had 

 potentially pure populations but genetic verification had not been 

 conducted. Of the remaining 181 rated reaches, 98 have westslope 

 cutthroat trout listed as a species present in their waters. 

 Potentially, the lower Clark Fork may still be providing extensive 

 habitat to this species of special concern. 



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