A monthlong ban on evening fishing will go into place Wednesday on much of the lower Madison River, a measure meant to protect the river’s trout from rising water temperatures.

The so-called “hoot owl” restriction will ban fishing between 2 p.m. and midnight each day on the Madison from Warm Springs fishing access to the river’s confluence with the Jefferson River near Three Forks. The closure is scheduled to end Aug. 15.

It’s the first summer the permanent version of the restriction is in place, marking a shift away from temporary closures ordered by fisheries officials when water temperatures surpassed 73 degrees on multiple consecutive days. Temperatures that high are a major stressor on trout, which are considered cold water fish.

The lower Madison typically gets hot in July and August, and hoot owl restrictions have been common there. Officials decided last fall to create the now annual closure to simplify the rules and 

help the fish.

“It’s predictable for everybody, and it’s just going to extend that protection to those fish,” said Travis Horton, regional fisheries manager for Montana Fish, Wildlife and Parks.

It’s also warm enough already. Temperature data from near Black’s Ford Fishing Access Site indicates the river has already topped 75 degrees multiple days this summer.

High temperatures are likely to come to other rivers around the state this summer, too. A wide swath of southwestern Montana is facing severe or moderate drought conditions, according to the U.S. Drought Monitor, and it’s likely hoot owls will be ordered on other rivers.

The new annual, monthlong closure on the lower Madison is the first of its kind in the state. The Montana Fish and Wildlife Commission approved it last October, scaling it back from FWP’s original proposal of a two-month restriction.

Horton said it’s not likely that sort of restriction could be applied to other rivers. He said the lower Madison is different in that it reaches those high temperatures and supports a healthy trout population. Other rivers that get that hot don’t support as robust a fish population.

Clayton Elliott, of Montana Trout Unlimited, said the closure makes sense on the lower Madison, and that his organization even supported the extended version. He added that temperatures even in the high 60s can be dangerous for trout, especially native species like the Yellowstone and Westslope cutthroat.

While some rivers have set thresholds for when the restrictions go into place, it’s left to the discretion of FWP officials on others, Elliott said. He thinks use of hoot owls may need to become more regimented in the future with climate change warming rivers.

“While the lower Madison is just a perfect example of where this tool makes sense, going forward, I think we’re going to see nothing but an increased need for hoot owl restrictions as temperatures warm,” he said.