5D: Reconnecting Fractured Streams to Restore Bear Lake’s Native Fish

Bonneville cutthroat trout, Utah’s state fish, live and move among diverse habitats to complete their life cycle. Bear Lake is home to one of only a few remaining lake-dwelling populations of the species. However, a century of land-use change, water development, and interactions with non-native fishes has created major declines in the population. Cutthroat trout must migrate into tributary streams to spawn and rear each spring. Diversion dams, culverts, and increased drought have fractured streams and limited the population’s access to tributary spawning habitats, curbing their reproductive success.

Over the last 25 years, projects aimed at reconnecting small streams to the lake by improving culverts and dams have helped fish reach their spawning areas (Figure 5.D.1). These changes have led to a significant increase in the population of wild Bonneville cutthroat trout, making recreational harvest of wild cutthroat trout possible again. It’s important for managers to keep finding and fixing barriers that block these trout from accessing stream habitats to ensure their population remains strong and stable.

For instance, in the fall of 2025, a culvert on North Eden Creek (on the east shore of Bear Lake) will be improved to let cutthroat trout swim upstream to spawn. Researchers at Utah State University are working with Trout Unlimited and the Utah Division of Wildlife Resources to study how this project will impact the number and size of trout living and spawning upstream. They’re also designing a long-term plan to monitor the success of this restoration effort.