CODY- In an ongoing effort to maintain a core conservation population of Yellowstone cutthroat trout on the west slope of the Bighorn Mountains, the Wyoming Game and Fish Department plans to remove brook trout from a section of South Paint Rock Creek later this month. 

In cooperation with the Bighorn National Forest and Bureau of Land Management, fisheries biologists plan to remove brook trout beginning July 30 by treating a 6-mile section of South Paint Rock Creek with rotenone, a chemical used in very small doses that is toxic to animals with gills. The treatment should be completed by August 2.  

South Paint Rock Creek on the west slope of the Bighorns is one of the few remaining Yellowstone cutthroat trout populations in the Bighorn Mountains. “Currently, Yellowstone cutthroat trout occupy 21 miles of habitat secured with a downstream natural barrier,” said Joe Skorupski, Cody region fisheries biologist. “The section of the creek treated will extend the core conservation population 6 miles.”  

On July 30, rotenone drip stations will treat the water for six hours within a 6-mile section of South Paint Rock Creek. From July 29 to Aug. 2, the treatment portion of the creek will be closed to entry.  “As an added safety precaution, we do not want anglers fishing in the area during the week of treatment,” Skorupski said. 

A deactivation chemical will be dispensed immediately upstream of the confluence of Paint Rock Creek for the entire time the rotenone is in the stream.