Yellowstone National Park announced Wednesday that all rivers and streams inside the park will be closed to fishing from 2 p.m. to sunrise each day, citing dangerously high water temperatures and low stream flows that can kill fish stressed by angling activity. The closures apply park-wide and add to existing restrictions on the Madison, Firehole, and Gibbon rivers below Norris campground that have been in place since July 15.
Park fisheries managers say warm, low-flow conditions reduce the oxygen content of water and leave fish — particularly native cutthroat trout — with little physiological reserve to survive the stress of being caught and released, even when anglers handle fish carefully. The closures are a precautionary measure, not a sign of a fish kill, and park officials say the restrictions will remain in effect until water temperatures and flows return to safe levels.
For Helena anglers who make the roughly two-hour drive south to fish the park's legendary waters, the new hours mean early mornings are still open. Fishing from sunrise through 2 p.m. remains permitted on most waters under the new rules, though the Madison, Firehole, and Gibbon remain closed around the clock below Norris. Anglers are advised to check current conditions at the park's website before heading out, as closures can expand or shift depending on conditions.
The Yellowstone restrictions come during the same regional heat event affecting Helena's air quality and straining the electrical grid this week. Montana Fish, Wildlife and Parks has issued similar midday fishing restrictions on some state-managed streams in recent summers during heat events, and anglers on waters outside the park should check for any active FWP advisories before fishing.