What is Rotenone?
Rotenone has been used for centuries by native tribes of Central and South America to catch fish for food. Since the 1930s, it has also been used by fishery managers to control and remove unwanted fish. Rotenone is a plant-derived substance that blocks fish's ability to uptake oxygen through their gills. Rotenone works in very low concentrations (as low as 50 parts per billion), and when properly applied to ponds, lakes, reservoirs, and streams, rotenone is an extremely effective tool for fish control. For more information on the use of rotenone, follow this link: Rotenone is the "reset button" for fisheries, but what is it, and how do fisheries managers use it?
What to Expect if you are Visiting the Area
Rotenone treatments are scheduled to occur for three consecutive weeks starting on August 11, 2025. Treatments will occur in Heather, Copper, Tin, and Platinum Lakes and the outlet streams immediately downstream of each lake. The Five Lakes Butte area will not be closed to the public; however, visitors will be asked to stay out of the treatment waters during this time. There will be additional traffic and Idaho Fish and Game presence in the area from July to September, and signs will be posted informing people of the project. Logistical preparations for Rotenone treatments will begin in early July. Fisheries crews will collect fish in the treatment streams below the lakes and move the native species (Bull Trout and Cutthroat Trout) to adjacent streams that will not be treated with Rotenone. Field crews will also be maintaning existing trails in the area to improve access to the treatment areas. A helicopter will be used to swing-load materials into high-elevation lakes before treatment. Campsites off Pot Mountain Road may be limited, but crews will not use Cedars Campground. The road into Five Lake Butte is narrow and rugged, so be aware of the additional traffic if you plan to visit the area. Feel free to ask the onsite crews about the project if you happen to be driving by.