is the largest freshwater sport fish in North America, originating 

 over 100 million years ago. The last observed white sturgeon in 

 the Kootenai was in 1981, during the annual spawning migration, 

 and it is feared this reach of the Kootenai may no longer be 

 providing spawning habitat to the white sturgeon. Its absence 

 may have resulted from the dramatic inversion of the river's 

 annual flow pattern and the modified seasonal water temperature 

 regime since the construction of Libby Dam, from past pollution 

 problems or over-exploitation. 



Declines in white sturgeon populations throughout the Columbia 

 River prompted the Northwest Power Planning Council to recommend 

 research to determine the impacts of dam operations on this 

 species. Preliminary results indicate that white sturgeon larval 

 behavior was negatively impacted by changes in temperature and 

 flow regime. Also, genetic isolation due to the trapping of 

 populations between dams may be causing selective mortality in 

 response to changes in the river. 



Easy access and an abundant population of rainbow trout, with 

 a chance for a trophy, contributed to the Class I sport fishery 

 for the Kootenai River from the dam to Kootenai Falls. A reduction 

 in suspended sediment loads and nutrient concentrations, and a 

 substantial modification of the thermal and flow regimes occurred 

 in the river in the early 1970s. The negative environmental 

 impacts of the dam were partially reduced through maintenance of a 

 minimum instream flow and a sophisticated selective water 

 withdrawal system in the dam which maintains river temperatures 

 between 50 and 60 degrees Fahrenheit from May to October. The 

 decrease in sediment production contributed to a nine-fold 

 increase in rainbow numbers in river sections below the dam, 

 although about half of the fish in 1977 were greater than 12 

 inches, compared to only 22 percent today. Current rainbow growth 

 rates are comparable to pre- impoundment growth. A notable 

 exception to the average fish size has occurred in the tailwater 

 area of the dam where a trophy fishery has developed for large 

 rainbow trout from five to 15 pounds. Biologists theorize these 

 "lunkers" are either resident fish taking advantage of fish being 

 passed through the turbines or may be migrating from Kootenay 

 Lake. 



Wildlife 



From a pair of harlequin ducks bobbing through a series of 

 rapids, to a Ural-Tweed bighorn ewe feeding along the river 

 benches as they green up in spring, the Kootenai River drainage 

 provides habitat for an abundance of rare and unusual wildlife 

 species, including the Cabinet Mountain grizzlies, the last 

 remnant population of Columbian sharp-tailed grouse in Montana, 

 bald eagles and ospreys. 



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