Brook trout removal planned for Binarch Creek in North Idaho to aid native trout

Idaho Fish and Game will begin a native fish restoration project in Binarch Creek, a tributary to the Priest River, in September. Fisheries staff in the Panhandle Region will use rotenone to remove nonnative brook trout, with the goal of benefiting westslope cutthroat trout populations.

This marks Phase 1 of a larger, collaborative effort between Fish and Game and the U.S. Forest Service. Future phases will include fish stocking, habitat improvements, barrier removals and other restoration work.

While the treatment will temporarily reduce fish numbers in Binarch Creek, it is designed to provide long-term benefits for native trout.

Why remove brook trout?

Brook trout were introduced to Binarch Creek in the 1940s. Over time, they have outcompeted and largely displaced native westslope cutthroat trout throughout the stream.

Why westslope cutthroat trout?

Westslope cutthroat trout are a native species prized by Idaho anglers. They thrive in cold, clean water and are a strong indicator of healthy aquatic ecosystems. Conserving their populations in the Priest River drainage is a priority identified in the 2025–2030 Idaho Fisheries Management Plan

Why rotenone?

Rotenone is a natural substance derived from tropical plant roots. It is highly effective at removing unwanted fish, targets fish only and breaks down quickly in the environment, making it a safe and widely used tool in fishery management. You can learn more about rotenone and how it's used by biologists here. 

— Idaho Department of Fish and Game