Introductions of Lahontan Cutthroat Trout into Omak Lake, Washington

Lahontan cutthroat trout (Salmo clarki henshawi) were introduced into 30.4-km 2 Omak Lake in 1968 to establish a sport fishery in an alkaline/saline system. After successful establishment of the population, these fish averaged 579 mm in fork length and 2,542 g in weight prior to opening of the first sport fishing season in 1975. Fishing mortality has greatly reduced the relative numbers of large cutthroat trout-those in the 600-800 mm size groups. Survey net catches, however, have remained comparatively constant from pre-sport fishery through post-sport fishery years. Fishing pressure on Omak Lake is light with approximately 5,400 man hours of effort expended annually to harvest 1,000 cutthroat trout that average 457 mm in length. The projected annual stocking rate is at least 100,000 fish that are 150 mm in length.