In its ongoing efforts to support bull trout and westslope cutthroat trout in Northwest Montana, Montana Fish, Wildlife and Parks is proposing a return to suppression work of non-native trout that provided, statistically, good results nearly 20 years ago.

The agency wants to remove non-native fish, including brown, brook and rainbow trout, and hybrid cutthroat-rainbow trout in the East Fork Bull River. 

According to a April 1 public notice, the goal of the work would reduce the non-native competition in an important adfluvial bull trout population and slow the spread of hybridization and reduce its impacts to remaining genetically unaltered westslope cutthroat trout, Montana's state fish, in the Bull River drainage.

Adfluvial fish are those that live in lakes as adults but migrate to tributaries to spawn.

The agency is seeking public comment on the proposal with a deadline of 5 p.m. April 15. To submit comments, email [email protected] or mail them to Montana Fish, Wildlife & Parks, 5427 Hwy 200, Thompson Falls, MT 59873.

The entire project may be found at https://fwp.mt.gov/public-notices/news/2026/apr/0401--bull-trout-a.nd-westslope-cutthroat-trout-enhancement-draft-cea.

According to the proposal, fish capture techniques would include backpack electrofishing and weir traps already being operated by the bull trout downstream fish passage program. 

Electrofishing includes using equipment that temporarily stuns fish, allowing them to be netted by FWP personnel. Non-native fish, such as those targeted in this proposal, would be released into Triangle Pond, a nearby community fishing pond, as conditions permit. The pond was formed from a former 8-acre gravel pit. 

Weir traps, an ancient invention, hold fish that travel into them before they can be collected. Traps would be located where they aren't likely to be seen by the public.  

FWP's suppression efforts could occur from July through November with no electrofishing occurring during bull trout spawning periods. Electrofishing crews would be restricted to fewer than four trips per week and only on weekdays, non-holidays and between the hours of 9 a.m. and 4 p.m.

Non-native trout larger than 9.8 inches captured would be relocated to the aforementioned pond.

Previous non-native fish suppression occurred from 2007-2009 in the lower 3.11 miles of the East Fork Bull River.

Fish capture techniques would include backpack electrofishing as well as weir and rotary screw fish traps. More than 3,500 brown trout, 1,900 brook trout and 60 rainbow trout, more than 3 inches long, were removed from the lower East Fork Bull River during three years of suppression. 

That work resulted in decreases of 74% in brown trout and 61% brook trout biomass from electrofishing sections, according to a 2010 study. From 2010 through 2020, brown trout and brook trout densities remained around 70% less than pre suppression densities, according to a 2022 study.

Bull trout are listed as a Threatened Species under the U.S. Endangered Species Act and have declined in population and size across Montana in the last several decades. Existing populations are generally small, and stable or in decline, and few robust populations remain.

Westslope cutthroat trout is one of two subspecies of native cutthroat native to Montana and together, they have been designated Montana's state fish. 

Many Montanans and visitors hold high regard for these native fish as an angling resource, an icon of the state, and a valuable component of the ecosystems in which it resides.

As such, the bull trout and westslope cutthroat trout are deeply engrained in the customs and lifestyles of residents and visitors of Montana.

FWP says the intent of the proposed action would support the following agency goals and objectives:

- Protected ESA listed threatened bull trout from hybridization and competition in one of the last remaining tributary strongholds for bull trout in the Lower Clark Fork River.

- Support substantial efforts by the upstream and downstream fish passage program to reconnect migratory native salmonid populations in the LCFR, specifically the Bull River drainage.

- Mitigate the loss of traits, through hybridization, that have evolved locally in westslope cutthroat trout.

- Retain the ecosystem role served by bull trout and westslope cutthroat trout, potentially avoiding adverse impacts to other organisms including insects, other fish, birds and mammals that may result if hybrids and non-native fish replace native salmonids completely.

- Maintain westslope cutthroat trout as a valued sportfish in the area affected by the proposed project, avoiding unacceptable social and economic impacts associated with losing the opportunity to fish for them.

- Reduce the likelihood of of federal Endangered Species Act (ESA) listing and protection of westslope cutthroat trout. ESA listing could limit public opportunity to fish for and otherwise interact with and enjoy this native fish species.

• Protect Montana’s state-designated fish, preventing further adverse impact to the affected populations and safeguarding against adverse impact to Montana’s cultural values associated with the species. 

Travis Rehm is the FWP fisheries biologist who prepared the Environmental Assessment for the proposal and Region 1 Fisheries Program Manager Mike Hensler signed off on it.

When Hensler, with 35 years experience, was named the manager in 2018, he told the Daily Inter Lake that promoting native fish in Northwest Montana was a primary goal.

He received the American Fisheries Society Lifetime Achievement Award for his leadership in the Columbia Basin redband trout status and recovery planning efforts.

“The work we’ve done with the redband (rainbow) trout over the last 20 years has been pretty special for me,” Hensler said. “It is the only rainbow trout that is native to Montana. We’ve been able to improve our knowledge of their range and that is our goal going forward in the next two decades - promoting native fish in Northwest Montana.”