"A dozen rivers are subject to “hoot owl” restrictions on afternoon fishing or all-out closures as biologists grapple with warming rivers and meager streamflows."
"Nearly a dozen rivers in western Montana and a handful of rivers inside the borders of Yellowstone National Park are under restrictions or closures as biologists seek to reduce angling-related sources of fish mortality.
On July 9, Montana Fish, Wildlife and Parks announced that portions of Upper Rock Creek, the Clark Fork River, the Bitterroot River and the entirety of Silver Bow Creek are closed to angling after 2 p.m. to protect fish during the hottest hours of the day. The previous day, hoot owl restrictions were announced for sections of the Ruby, Big Hole, Beaverhead and Smith rivers and for the entirety of the Jefferson River. The Sun River and the Madison River, perhaps the state’s most popular angling destination, were placed under hoot owl closures particularly early this year — July 2 for the Sun River and June 19 for the Madison River above Hebgen Lake.
FWP initiates hoot owl closures when river temperatures reach 73 degrees for three consecutive days and uses angler pressure and flow-based criteria when considering full closures. Trout are particularly susceptible to disease spread and other sources of mortality from late July through late August, when meager flows, rising temperatures and low dissolved oxygen levels converge. Water temperatures above 77 degrees can be lethal to trout."
Amanda Eggert reports for the Montana Free Press July 15, 2025.
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