Yellowstone lifts fishing closure on rivers and streams
Yellowstone National Park responded to high water temperatures and unprecedented low stream flows in rivers and streams by instituting a fishing closure during the afternoon and evening (after 2 pm) as of July 24, 2021. Conditions at the time were stressful and even fatal for trout.
Since conditions have improved, the fishing closure on park rivers and streams has been lifted as of Aug. 20, and anglers can resume fishing all day (sunrise to sunset) as specified in the Fishing Regulations booklet. https://www.nps.gov/yell/learn/news/210820.htm