Development, Improvements, and Enhancements
In 1972, Montana Fish, Wildlife & Parks (MFWP) constructed a gabion fish barrier in the lower reaches of Elkhorn Creek of the Beartooth Wildlife Management Area. Westslope cutthroat trout (WCT) hybridized with rainbow trout were removed from approximately three miles of stream above the constructed barrier. Genetic samples collected in 1996 indicated the population was non-hybridized, but in 2002, additional samples indicated recent hybridization likely because of a failure of the gabion fish barrier. A sample collected in 2008 revealed that the WCT population in Elkhorn Creek had become a hybrid swarm with some level of hybridization in every individual; also, a brook trout was captured upstream of the gabion fish barrier. An alternate barrier site was identified approximately three miles upstream, which features bedrock control points and a narrow incised channel that greatly increases the functionality of the barrier. The proposed action is to construct a barrier to non-native fishes and remove heavily hybridized WCT upstream of the barrier with electrofishing or piscicides.