Fishing restrictions placed on North Fork due to warm water

In an unprecedented decision, state officials have placed fishing restrictions on the North Fork Flathead River due to record water temperatures and dropping flows.

The Montana Fish, Wildlife and Parks' hoot-owl restrictions went into effect Wednesday and prohibit fishing from 2 p.m. to midnight each day. The restriction will stay in effect until conditions improve.

Montana Fish, Wildlife and Parks says it received approval from the Montana Fish and Wildlife Commission and collaborated with Glacier National Park on the restriction, which will extend the full length and both sides of the North Fork from the U.S.-Canadian border to the confluence with the Middle Fork Flathead River near Blankenship Bridge.

Fishing restrictions are designed to protect fish that become more susceptible to disease and mortality when conditions, such as low flows and high water temperatures, combine with other stressors, including catch-and-release fishing.

Biologists have been closely monitoring the water temperatures of local rivers and streams amid a summer heat wave in northwest Montana. Water temperatures in the North Fork have been near or above daily records since early July. Elevated water temperatures negatively impact the health and survival of native westslope cutthroat trout and bull trout.

It is common for the state to implement hoot-owl fishing restrictions in sections of rivers across the state every summer. However, the state has never implemented hoot-owl restrictions in the Flathead drainage until now.

The Statewide Fisheries Management Plan identifies different temperature criteria for different species of native trout. The temperature criterion for westslope cutthroat trout is met when water temperatures reach or exceed 66 degrees Fahrenheit for three consecutive days. The criterion for bull trout is 60 degrees, also for three consecutive days.

Fisheries biologists are also concerned about increasing water temperatures and affected trout populations in the following rivers and adjacent tributaries:

• Middle Fork Flathead River

• South Fork Flathead River

• Mainstem Flathead River upstream of Old Steel Bridge in Evergreen

• Swan River

• Thompson River

The state is not recommending hoot-owl restrictions at this time on these other stretches of water but is encouraging anglers to voluntarily limit their fishing to the morning hours when water is coolest and fish are less stressed. Additional fish stress and mortality can result from human handling when trout are caught and released by anglers.

Officials will continue to monitor conditions on these rivers and make adjustments as needed.