Robb Creek is dominated by brook trout, but maintains a small population of WCT. Mottled 

 sculpin are also present. A survey in 1991 estimated catchable size fish at 496 per mile. Brook 

 trout averaged nearly eight inches in length, with the largest exceeding 12 inches. Westslope 

 cutthroat trout averaged only 6% of the game fish population. Sizes ranged to 9 inches in length. 

 Habitat in the surveyed area consisted primarily of a network of beaver ponds connected by short 

 reaches of stream. The majority of habitat was provided by the ponds or woody debris 

 associated with the dams. Livestock impacts had influenced portion of the inventoried stream 

 reach. 



Rock Creek contains exclusively WCT. Population densities range fi-om 160 to 300 catchable 

 size fish per mile, with the largest fish exceeding 12 inches in length. Fish habitat is limited 

 throughout most of the stream. Two reservoirs appear to provide over-winter habitat to a 

 significant portion of the population. Primary factors influencing the habitat include the outlet of 

 the upper reservoir which has eroded a 15 foot gully for approximately 200 yards. This has 

 largely obliterated habitat features for a significant distance downstream. In addition, a natural 

 slump has confined the channel resulting in steep, eroding banks, which continue to introduce 

 high levels of sediment. Livestock are also impacting streambanks and riparian condition. 



The genetic status of this population has not been adequately determined. Preliminary analysis of 

 cutthroat collected in 1995 indicated this population was genetically pure. Subsequent fish 

 collected in 1997 and analyzed in 1998 suggest that the population is either slightly hybridized or 

 carries a rare WCT allele that is electrophoretically indistinguishable fi"om that characteristic in 

 Yellowstone cutthroats or rainbow trout. 



Fisheries inventories have not been conducted on Crows Nest Creek, Taylor Creek, Swamp or 

 Indian Creeks, thus their status as fisheries is not known. 



Status of Westslope Cutthroat Trout in Montana 



In June, 1997, the Fish and Wildlife Service receive a formal petition to list WCT as threatened 

 throughout its range. In January, 1998 the Service received an amended petition, fi-om the 

 copetitioners, which contained a substantial amount of new information to support their 

 requested action. The Fish and Wildlife Service will likely make a decision on WCT listing by 

 July, 1999. 



Genetically pure populafions of WCT presently occupy 2.9% of their historic distribution. A 

 viability assessment on 144 populations (90 - 100% genetically pure) in the Upper Missouri 

 River drainage was completed in 1996. Results indicated most populations are at a high risk of 

 going extinct. Based largely on the results of this assessment and recommendations from the 

 WCT Technical Committee, the Forest Service and Bureau of Land Management are giving 

 stream habitats with slightly hybridized WCT populations (90 - 99% pure) the same emphasis as 

 those supporting entirely pure populations. Similarly, the WCT Conservation Plan (in draft form, 

 but likely finalized within a couple of months) stipulates that 90 - 99% pure populations must be 

 managed as pure until a watershed plan is formalized, defining conservation objectives. If that 

 population or stream is not part of the specified objectives, management will revert back to sport 



