Status of Lahontan Cutthroat Trout in the Coyote Lake Basin, Southeast Oregon

Abstract

Lahontan cutthroat trout Oncorhynchus clarki henshawi occur in streams flowing north through the Trout Creek and Oregon Canyon mountains into pluvial Coyote Lake in southeast Oregon. The Coyote Lake basin has the only native population of Lahontan cutthroat trout in Oregon that is without threat of hybridization and is broadly distributed throughout a drainage. In October 1994, the number of Lahontan cutthroat trout in the basin was estimated at 39,500 fish, and fish were limited to 56 km of the potential 114 km of stream habitat available. Distribution was limited by dry channels and thermal and physical barriers to movement, which created two disconnected populations in the Willow Creek and Whitehorse Creek drainages and influenced population density, structure, and life history. Lahontan cutthroat trout in the Coyote Lake basin would be more secure if aquatic habitat were improved to allow the two populations to expand their current distributions and become more connected.