Southwest Montana Fishery Updates

Illustration of Montana fishery master plan indicators.

Last year, when the George Grant Chapter of Trout Unlimited of Butte held its annual state of the fishery program, featuring local FWP fisheries biologists, we heard the news that our southwest Montana world-famous fisheries were in trouble. Trout numbers on the Big Hole River (and others) were far down from what they were just a few years earlier, especially brown trout.

 As the season progressed, with extreme drought and warming waters, Montana’s Fish, Wildlife & Parks adopted emergency regulations on several Montana rivers.

When Trout Unlimited held this year’s state of the fishery program, I suspect some people were hoping that last year’s low trout numbers were all a mistake and happy days are here again.

FWP biologists Matt Jaeger, who manages the Beaverhead and Ruby River, and Jim Olsen, who manages the Big Hole River and its watershed, presented their observations.

First, not all news is bad. Jaeger characterized the upper Beaverhead River, from below the Clark Canyon Reservoir to Pipe Organ Bridge as a “bright spot,” in the state, with good populations of trout, both brown and rainbow, noting that almost all the Beaverhead’s rainbow population is in that upper stretch.

On the flip side, 2022 is anticipated to be another dry year, with irrigators getting reduced water allocations for the growing season, and water releases from the dam to reduce to 25 cubic feet per second (CFS) in mid-September.

 This will be another tough year for the Ruby River, with a 20 percent reduction in water allocations to irrigators. Last year, the lower part of the river near the confluence with the Beaverhead, essentially went dry. This spring it may be wet, but it’s far from healthy.

Jaeger also presented some unexpected findings from the Clark Canyon and Ruby Reservoirs based on study of otoliths (ear bones in fish). The otoliths develop rings as the fish grows, and chemical analysis of those rings can indicate where the fish were in various stages of life. Notably, hatchery-raised fish will have an early life in different waters, whereas a wild fish will show similar waters all their life. Surprisingly, despite extensive stocking in these reservoirs, most of the fish sampled were wild fish.

 Based on this spring’s surveys on the Big Hole, biologist Jim Olsen reported a slight uptick in fish numbers, especially with smaller brown trout, though he conceded that any apparent increase in trout numbers is likely within a margin of error, so there’s nothing to cheer about at this point.

Olsen also noted that the Big Hole River is having 90,000 angler days annually, with resident and non-resident use about equal, twice as much use as a decade ago, though there’s no effective way to determine what effect this has on the fishery. When asked what the effect of 90,000 angler days is, Olsen replied, “I don’t know, but it’s more than 45,000 days.”

Olsen also reported on the project on French Creek to remove non-native fish and restore a native fish population. The basic work has been done. DNA studies will be done in early summer to determine if there are still non-native fish in the waters. If not, restocking with native westslope cutthroat trout and grayling will begin this year and continue for five years. After that time, the streams in the watershed will presumably reopen to angling.

A continuing theme in the presentations was a proposed statewide management plan that would use percentiles of fish numbers, from low to high, to determine if immediate changes are needed in angling regulations, such as season closures or reduced creel limits, or liberalizing if fish numbers are high. The preferred standard is a stable 25th -75th percentile trout population. Note the photo of a PowerPoint slide illustrating those ranges.

 On a happy note, since that April TU meeting, we’ve had a lot of weather systems come through our part of Montana, and the latest snowpack figure in the Jefferson River watershed, which includes the Big Hole River system, indicates that the snowpack is at 99 percent, and since that figure as of the end of April, we’ve had more snow, so the current snowpack is now over 100 percent of average.

 That should have everybody feeling better about the coming season.

 Paul Vang’s new book, “Golden Years, Golden Hours,” is available at How Novel, The Second Edition, Isle of Books & Books, and The Corner Bookstore, or online at

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