WCT Multi-state Assessment February 10, 2003 



Jabcobs 2002). We have documentation that a few unnamed streams that did not appear on 

 LLID hydrography layers actually support WCT, but these streams were not included in our 

 assessment. Comparisons between regions that did and did not include unnamed streams would 

 not be valid, but comparisons within each of these two regions should be. Estimated lengths of 

 habitats historically and currently occupied by WCT will be higher for those HUC's that 

 included unnamed streams, but proportions of habitats occupied should be comparable across 

 their range. 



Assessment Teams 



A total of 1 12 fisheries professionals from 12 state, federal, and tribal agencies and private firms 

 provided the infomiation that was used in this assessment. These individuals met as part of nine 

 different assessment workshops (Appendix A). In addition to the fisheries professionals, 21 GIS 

 and data management specialists also participated in these workshops to assist with data entry 

 and display of status information for on-site editing of data. Information stored in statewide 

 databases was available in hard copy and on computer for each of these assessment workshops in 

 tabular and map formats. From two to five information technology and data entry personnel also 

 attended each workshop to provide technical support and enter information into computer 

 databases. All fishery professionals were asked to bring field data summaries for their areas of 

 responsibility so existing databases could be updated and used in this assessment. At each 

 workshop fishery professionals who had relevant information or knowledge within each 4 code 

 HUC worked collaboratively to fill in data forms that were immediately entered into a computer 

 database. Often individuals worked on several 4"^ code HUC teams. As data were entered from 

 paper data forms into the computerized database at least one individual from each 4' code HUC 

 team ensured that data were entered accurately. The fisheries professionals that completed these 

 assessments had experience levels ranging from several months to several decades. Collectively, 

 these fishery professionals had a combined total of 1,818 years of professional fisheries 

 experience, of which 1,151 was directly applicable to WCT. The majority of participants had 

 Master's of Science college degrees (68), four had PhD degrees, and all had at least a Bachelor 

 of Science degree. 



Historical Range 



For the purposes of this assessment European "discovery" of the west was set as the benchmark 

 time (-1800) for the historical range of WCT. While it is likely that the distribution of WCT has 

 expanded and contracted over geological time, written documentation of historical distribution 

 began around 1800. As Behnke (1995) states (p. 79), "The original distribution of westslope 

 cutthroat trout is not known with certainty.'" Using Behnke's (1995) delineation of historical 

 range as a starting point, we included all streams within any 4th code HUC's that had any 

 streams Behnke identified as being historically occupied. Fishery professionals were then asked 

 what stream segments should be excluded from historical range based on evidence for exclusion. 

 Evidence for exclusion included: geological barriers with no evidence that WCT inhabited 

 waters above the barriers; tectonic events that would have made regions uninhabitable and were 

 likely either not colonized or ancient populations had gone extinct and not re-colonized prior to 

 1800; and habitat unsuitability based primarily on thermal regime and stream channel gradient 

 (Appendix B). In a few cases entire 4th code HUC's were excluded. Information sources that 

 supported inclusion of stream segments as historically occupied were noted, where available, and 



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