The Wyoming Game and Fish Department lifted its voluntary fishing closures on the Bighorn River, effective immediately, according to a Sept. 11 announcement from the agency's Cody Region. Cooler weather has moderated water temperatures across the Big Horn Basin, and continued cooling in the forecast is expected to keep stress on local trout populations at safer levels.
The voluntary closures had been in place since early August, when the agency asked anglers to avoid or restrict fishing on stretches of the Bighorn below Boysen Dam because river temperatures were regularly exceeding 70 degrees Fahrenheit in the afternoon and evening. Under the earlier restriction, the reach from Hot Springs State Park downstream to the Skelton Boat Ramp had been closed to all voluntary catch-and-release fishing, while the reach from Wedding of the Waters downstream to the Hot Springs State Park Boat Ramp had been closed between noon and sunrise.
Wyoming Game and Fish has documented that summer temperatures in the Bighorn through Thermopolis often exceed 70 degrees in July and August, and that a combination of extended hot air temperatures and low flows in 2026 had prolonged the stressful conditions this year. Warm water carries significantly less dissolved oxygen, which makes recovery difficult for trout that fight a hook and are then released.
With the closures lifted, catch-and-release fishing may resume on the affected reaches, though the agency reiterated its trout-handling guidance for warm-weather conditions. When stream temperatures approach or exceed 70 degrees, catch-and-release fishing should be paused for the day. Temperatures above 75 degrees are considered hazardous to trout, and brief exposure above 80 degrees is often fatal. At 65 degrees, the agency encourages anglers who plan to keep fish to harvest their legal limit rather than release.
Recommended handling includes minimizing fight time, keeping fish submerged while removing hooks, and using barbless hooks. Anglers are encouraged to carry a pocket stream thermometer and to continue monitoring water temperatures through the fall, since conditions are expected to keep fluctuating. Wyoming Game and Fish maintains a statewide Fishing in the Heat resource with the current list of voluntary closures across the state.
