KALISPELL — Montana Fish, Wildlife & Parks biologists are closely monitoring the water temperatures of northwest Montana rivers and streams and could propose fishing restrictions this summer to reduce fish stress and mortality.
Amid a summer heat wave, water temperatures across the region are approaching stressful levels for trout, particularly westslope cutthroat and bull trout. Anglers can help reduce stress to cold-water fish like trout by fishing during the coolest times of day and fishing areas with less stressful temperatures and conditions, such as larger lakes or reservoirs, or higher elevation waterbodies. Other tips are listed below.
It is common for FWP to implement “hoot owl” fishing restrictions in sections of rivers across the state every summer. Hoot owl restrictions prohibit fishing between 2 p.m. and midnight until conditions improve. If conditions deteriorate further, full fishing closures could be implemented.
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.
It is uncommon for FWP to enact fishing restrictions in northwest Montana. FWP has never implemented hoot owl restrictions in the Flathead drainage. However, this summer fisheries biologists are concerned about increasing water temperatures and affected trout populations in the following rivers and adjacent tributaries:
- North Fork Flathead River
- Middle Fork Flathead River
- South Fork Flathead River
- Mainstem Flathead River upstream of Old Steel Bridge in Evergreen
- Swan River
- Thompson River
FWP’s drought policy provides for angling restrictions when flows drop below critical levels for fish, when water quality is diminished, or when maximum daily water temperatures reach certain levels. FWP may request the Montana Fish and Wildlife Commission restrict or close fishing based on those criteria.
FWP’s 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.
Based upon current conditions, FWP is not yet requesting any fishing restrictions or closures anywhere in northwest Montana. But FWP is encouraging anglers to voluntarily limit their fishing to the morning hours when water is coolest and fish are less stressed.
All stress to fish at this time of year is cumulative. Anglers can help reduce stress for fish by following these practices when catching and releasing fish, though fish mortality may still occur:
- Remember: Only single-pointed hooks are allowed in the Flathead drainage upstream of Teakettle Fishing Access Site on the mainstem Flathead River, and on the Swan River from Piper Creek Bridge downstream to Swan Lake. Treble hooks and double hooks are prohibited in these stretches.
- Fish during the coolest times of day, where permitted.
- Land the fish quickly.
- Wet your hands before handling the fish.
- Keep the fish in water as much as possible.
- Remove the hook gently. Using artificial lures with single and barbless hooks can make hook removal faster and easier.
- Let the fish recover before releasing it.
- Consider fishing areas with less stressful temperatures and conditions, such as larger lakes or reservoirs, or higher elevation waterbodies.
For more information and updates, visit https://fwp.mt.gov/news/current-closures-restrictions/waterbody-closures or contact the FWP Region 1 office at 406-752-5501.
