PREFACE 



l^is assessment addresses the impacts to the wildlife popula- 

 tions and wildlife habitats due to the Libby Dam project on the 

 Kootenai River and orevious mitigation of these losses. Two 

 previous reports (Blair 1955a, U.S. Dep. Inter. 1965) assessed the 

 potential impacts of the Libby Dam project. Blair (1955a) concen- 

 trated on big game - primarily deer, elk and bighorn sheep - and 

 reported there would be only minimal impacts to the other wildlife 

 species, with the exception of beaver and muskrat which would lose 

 the available habitat within the impoundment area. U.S. Dep. 

 Inter. (1965) was less conservative in predicting the probable 

 impacts of the project and included more species then the previous 

 assessment (Blair 1955a); however, some of the impacts predicted by 

 the assessment could not be substantiated by available data. Pre- 

 vious mitigation projects were based on the impacts addressed by 

 the Fish and Wildlife Service (U.S. Dep. Inter. 1965). The current 

 assessment, funded by Bonneville Power Administration, documents 

 the best available information concerning the impacts to the wild- 

 life populations irthabiting the project area prior to construction 

 of the dam and creation of the reservoir. Many of the impacts 

 reported in this assessment differ from those contained in the 

 earlier document compiled by the Fish and V7ildlife Service; how- 

 ever, this document is a thorough compilation of tl'ie available data 

 (habitat and wildlife) and, though conservative, attempts to real- 

 istically assess the impacts related to the Libby Dam project. 

 ^Jhiere appropriate the impacts resulting from highway constructic-i 

 a:-id railroad relcK-.aticn were included in the assessment. This was 

 consistent with the previous assessments. 



In order to develop and focus mitigation efforts, it was first 

 necessary to estimate wildlife and v/ildlife habitat losses attri- 

 butable to the construction and operation of the project. The 

 purpose of this report was to document tlie best available informa- 

 tion concerning the degree of negative and positive impacts to 

 target wildlife species. Benefits to non-target wildlife species 

 will be identified during the development of alternative mitigation 

 measures . 



Reported loss estimates represent losses considered to have 

 occurred during one point in time, which tends to result in more 

 conservative estimates, except where otherv/ise noted. Vthen possi- 

 ble, quantitative loss estimates were developed based on historical 

 information from the area or on data from similar areas. Qualita- 

 tive loss estimates of low, moderate, or high with suppcirting 

 rationale were developed for each target species. These qualita- 

 tive estimates will provide th:e basis for determiriing relative 

 degree of mitigation efforts as agreed to by the participating 

 entities. Quantitative loss estimates will provide additional 

 support for the level of mitigation necessary and will aid in 

 evaluating the success of future mitigation projects. 



