Bull Trout

In Bighorn (Ram) Creek, in the Wigwam River drainage of British Columbia, the Threatened bull trout complete their 50-mile cross-border International spawning migration from Lake Koocanusa in the Kootenai River drainage in Montana. As many as five thousand of the eight- to fifteen-pound bull trout migrate upstream, where they pair off and each bury their few thousand eggs in spawning redds (nests), constructed in the clean gravels of clear 40-degree groundwater and spring-fed tributaries. The eggs incubate over the winter and the bull trout fry emerge in spring, to spend 1-3 years rearing before completing the downstream migration back to the reservoir where they mature and complete the cycle.