State of the Big Hole Fishery

Biologist Jim Olsen (photo courtesy of GGTU)

Fish like water, and fish do well when there’s lots of water.

That was a takeaway from the last program meeting of the season of the George Grant Chapter of Trout Unlimited. Jim Olsen, the FWP fisheries biologist for the Big Hole River watershed was on hand to present the State of the Big Hole Fishery.

There is now a mass of statistical data about fish populations on the Big Hole River, going back to the 1970s, when the now-retired Big Hole biologist, Dick Oswald, started electrofishing the river to get a sampling of the fish population.

Oswald, who also supervised the Beaverhead River fishery, created extensive documentation that low water years result in lower fish populations. That might not seem like rocket science, but I recall presentations from Oswald in which he reported a lot of pushback from some water users, until he showed them the scientific data.

Olsen, who has been working on the Big Hole River for ten years, had data that continues to show that fish populations are generally higher following big water years, with 2011 a prime example. 2018 will likely be another of those years that will result in increased fish populations next year.

Of special interest was a look back at the impact of special regulations on portions of the Big Hole River. The Special Regs first went in effect in 1981 on the Divide to Melrose section of the river. In 1988, the upstream portion expanded to Dickie Bridge. The special regulations cut daily “catch and cook” limits from five trout to three trout, with a slot limit of fish that had to be released.

Prior to 1981, fish populations in the river tended to be around 500 fish per mile. After the special regulations went into effect, the overall size of fish in the river increased, as did overall numbers of fish. On the other hand, the numbers of large fish, trout of 20 inches or more, declined. Greater numbers of fish mean more competition for available food.

Olsen also reported on angling pressure on the Big Hole. In 2015, there was an estimated 93,478 angler days on the Big Hole River, an increase from earlier surveys. If that seems like a lot of pressure, Olsen noted that angler days on the Madison River were 298,000.

Olsen also commented, briefly, on proposals to re-establish native fish populations in the French Creek watershed, which has generated a certain amount of controversy from people opposed to the project.

Olsen underlined that one of the reasons for doing the project on French Creek is because virtually the whole watershed is on public land. He also noted that the proposed project is one of the reasons that the Fish & Wildlife Service has not put the threatened arctic grayling on the endangered species list. If the project were to be canceled it would likely change the classification.

In any event, the period for filing comments on the French Creek project has been extended to May 30. Comments can be sent by email directly to Olsen at

I’m going to editorialize a bit.

I’ve been following comments in the local press opposing the project and can’t help shaking my head in amusement and despair. The arguments against the project are primarily designed to stir up anger, but don’t present any scientific basis for objecting to the project. After the TU program, I asked Olsen if anybody, at various public events, has presented anything that hadn’t been presented, and scientifically shot down, during the extended fracas regarding Cherry Creek on the Madison River. He said there was nothing that hadn’t been heard before.

I look forward to a westslope cutthroat fishery in the French Creek drainage. I’ve occasionally fished a small tributary on Rock Creek. Most of the creek isn’t much wider than six feet, but I’ve caught wild cutthroat trout of up to 20 inches there.

I’d love to have that opportunity closer to home. There are plenty of other creeks that will still give people the opportunity to catch all the brookies they can eat. Cutts are special.

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