Two Years After Calling for a Cold Water Fisheries Task Force, Southwest MT Trout Populations Fall to Historic Lows

You don’t have to look far to see that Southwest Montana’s world-renowned wild trout fisheries have been on the decline for the past several years. A suite of troubling conditions – low snowpack and dewatered rivers, nutrient pollution driven noxious algal blooms, warming water temperatures, fish die-offs and understudied diseases, and increased recreational pressure – have stressed our fisheries the past few summers, and now, Montana Fish, Wildlife & Parks’ (FWP) latest fish count data show trout populations in the Jefferson Basin have crashed to historic lows with a near complete loss of recruitment of juvenile trout. The Montana Standard reported on the crash here.

Contact Governor Gianforte and ask him to address the population collapse in our cold water fisheries.

Big Hole River Fish Counts Collapse

The Beaverhead, Ruby, Jefferson, and Big Hole Rivers are all experiencing massive declines in trout numbers, but the Big Hole is faring the worst. Troubling data shows Southwest Montana’s premiere blue ribbon fishery and the last habitat in the lower 48 with fluvial Arctic grayling has plummeting populations of both brown and rainbow trout. 

Jerry Creek:

  • Latest sampling in 2022 found just over 400 brown trout per mile, compared to over 1200 per mile in 2013 
  • Rainbow trout per mile have decreased from 2,250 in 2008 to just 500 in 2022


  • In Melrose, 1900 brown trout per mile were counted in 2014. Less than 10 years later and only 400 fish per mile remain in 2022.  
  • Rainbow trout per mile have been reduced by ⅔ since 2016, from 600 fish per mile to less than 200 in 2022.


  • In 2012, nearly 1500 brown per mile were recorded. Ten years later, only 300 fish per mile were counted, cutting the population to ⅕ th of the 2012 total.
  • Rainbow trout per mile have decreased from 800 in 2014 to less than 300 in 2022.

As a result of these staggeringly low numbers, FWP is proposing a spawning closure in sections of the Big Hole from October through April where fish density is fewer than 1200/mile. River stretches with 800 fish/mile or fewer are proposed for exclusively catch and release fishing.

Beaverhead River Fish Counts

In the Beaverhead River, brown trout populations >203 mm per mile have also declined over the last decade. 

Ruby River Brown Trout 

In the Ruby, brown trout populations are at 30-year lows. At Vigilante, there are approximately 700 brown trout >203 mm per mile, and less than 500 brown trout per mile at Silver Springs. 

Local fishing guides are already reporting cases of sick fish on our rivers. Reports of dead brown trout and brown trout with cauliflower sores have been caught on the Beaverhead in the last week, and mountain whitefish caught over the weekend in the Big Hole River were immediately presenting lesions. 

What’s to Blame for the Widespread Trout Population Crash?

At this time, FWP doesn’t know exactly what’s causing trout population crashes throughout the Jefferson Basin. The Montana Standard article noted several theories including fungus and bacterial infections caused by poor habitat and water quality conditions, but dead trout samples from last year are still in freezers and state biologists have still not had those samples studied for possible diseases or infections. 

Why FWP has failed to conduct testing on the fish samples and allocated the necessary resources to address this emergency is an open question. FWP’s Region 3 Fisheries Manager position has been vacant for over a year and a half, and additional funding and staffing shortages have also hindered the agency. Despite a record state budget surplus and tens of millions of resources in the Habitat Montana program, the Governor and FWP failed to request funding resources from the legislature to conduct sampling and testing. Lack of funding and resource allocation to conduct sampling and testing shouldn’t be a roadblock. 

The Big Hole River Foundation, which has been collecting water quality data on the Big Hole River since 2020, has hypothesized that while the river and trout populations are stressed by water quantity, water quality issues and eutrophication, climate change, development, and recreational pressure, this specific basin-wide crash may be fueled by disease and thus, expert scientists are needed to study the collapse and guide science-based management decisions. Check out this detailed explanation of the fish data and population numbers from the Big Hole River Foundation.

Call for Cold Water Fisheries Task Force 

You might recall that in the summer of 2021 a broad coalition of outfitters, guides, fly fisherman, businesses, and over one-thousand citizens called on Governor Gianforte to establish a Cold Water Fisheries Task Force to address our declining wild trout fisheries. The request highlighted the deteriorating conditions seen on southwest Montana’s rivers, with an immediate call to convene experts and the public to find science-based long-term solutions to protect our iconic cold water fisheries. 

Two years later, and none of the organizations, businesses, or concerned community members have received a response from the Governor. Trout numbers have declined every year since this administration has been in office, yet our elected officials and state agencies continue to sit on their hands and ignore the thousands of Montanans that asked for assistance. 

In Beaverhead County, fly fishing, hunting, and the outdoor economy generates more than $167 million each year and creates over 1,400 jobs. The collapse of wild trout fisheries in the Jefferson Basin will shutter numerous local businesses and jobs that depend upon healthy fisheries, and further inaction by the State will shatter the local economy.

Ask Governor Gianforte to follow through on our two-year old request to establish a Cold Water Fisheries Task Force to rectify the troubling situation in the Jefferson Basin and take proactive measures to prevent this from occurring on other Montana rivers.

Immediate Action is Critical

It’s past time for the Governor and FWP to step up and take action to protect the Big Hole, Beaverhead, and Ruby Rivers. Governor Gianforte needs to finally fulfill our request and form a Cold Water Fisheries Task Force, much like other task forces the Governor has already established, to bring together experts and input to address these critical issues.

With millions of dollars in the Habitat Montana account and an emergency account at his fingertips, the Governor needs to allocate funding toward staffing, studying, and identifying the cause of the collapse of our fisheries. The Governor has the authority to release funds so FWP can complete the necessary studies, and needs to treat this catastrophe with the urgency it deserves.

Tell Governor Gianforte to protect the Jefferson Basin and Southwest Montana’s communities by forming a Cold Water Fisheries Task Force now.