“The water temperature has been above 70 degrees for several days in a row,” said Travis Duncan, a spokesman for Colorado Parks and Wildlife. “More closures are likely as we move forward in the season.”
On Tuesday, the Montana Department of Fish, Wildlife and Parks imposed a “hoot owl” ban on the Missouri River, one of the most popular trout fishing sites in the state, between Helena and Great Falls because of warmer water temperatures. The rule prohibits fishing after 2 p.m. (the term “hoot owl ban” stems from the early days of the lumber industry. Lumberjacks work on late summer mornings, when it’s colder, as the forests are dry) And this increases the risk of chain saws or other tools igniting. Lumberjacks often hear owls during morning shifts.)
Although restrictions are sometimes imposed during the summer season, this year is unusual.
Eileen Rice, administrator of the state’s Department of Fisheries, said “what we know historically is unprecedented” to the extent that the limits have been imposed.
Brown trout populations in the southwestern part of the state have declined over the years, including the Big Hole, Ruby, Yellowstone, Madison, and Beaverhead rivers, some of the top destinations for fly fishers.
This year on the Big Hole River, for example, on one of the most popular stretches, the May census found 400 brown trout per mile, down from 1,800 in 2014. The Beaverhead River has declined from 2,000 brown trout per mile to 1,000. And those calculations were conducted early in the season, before the onset of extreme conditions this summer. The state is considering long-term restrictions on all of these rivers, which could include releasing all brown trout or stopping fishing in some places.