Fall Chinook Salmon and Steelhead Update: Sept. 24

Hi everybody. With recent changes in the fall Chinook salmon season, I felt it was important to provide an update on the status of this fishery including whether harvest restriction on adipose-intact adult fall Chinook salmon will continue past September 26. And while I was at it, I thought it would also be a good time to provide an update on the status of our steelhead returns.

Fall Chinook

Last week (Sept. 16) Idaho Fish and Game closed harvest of adipose-intact adult fall Chinook salmon in Idaho from Friday, Sept. 19 through Friday, Sept. 26. This closure occurred to ensure the sport fishery did not exceed our allowable take on wild fish.

In a previous update I provided (fall chinook update 9/12/25), I indicated that we were concerned that warm water temperatures in the Columbia and Snake rivers could result in in lower survival of fall Chinook salmon during their migration from Bonneville Dam to Lower Granite Dam. If this occurred, fewer wild fish could make it to Idaho and significantly reduce the allowable impacts we would be allowed to have during our sport fisheries. Since this last update, water temperatures have starting to cool and fall Chinook salmon have resumed their migration. Unfortunately, the data suggests that survival is lower than typical, and the number of adult wild fish that will make it past Lower Granite Dam will be somewhere between 4,000 to 5,200. The significant of this estimate is when fewer than 5,040 wild fish make it past Lower Granite Dam, our allowable impacts drop from over 10% to 6% of the wild return. If the wild run comes in under 5,040 adult fish, then we'd likely have only enough impact to maintain a harvest fishery on adipose-clipped fish. If the wild run comes above 5,040 adult fish, then we'd have enough impact to go back to providing a harvest fishery on both adipose-intact and adipose-clipped fish. Right now, we believe the risks are too great to reopen harvest on adipose-intact fish. For that reason, we have decided to prolong our closure on the harvest of adipose-intact adult fall Chinook salmon for another week (through October 3, 2025). This will give us time to better estimate how many wild fish will make it past Lower Granite Dam and whether we can reopen harvest of adipose-intact fish.

To reiterate, the fall Chinook salmon fishery in Idaho will continue through at least October 3, 2025, where ONLY adipose-clipped adult fish can be harvested. All adult fish with an adipose fin must be released. Adipose-clipped and unclipped jacks can still be harvested. In my discussions with Washington and Oregon fishery managers, they will also continue with this closure.

Recently, daily counts exceeding 900 adult fall Chinook have been observed at Lower Granite Dam, so fishing could pick up in the confluence area of the Snake and Clearwater rivers.However, don't expect to go out there and catch your limit as average catch rates have exceeded 20 hrs/fish recently . Additionally, we are getting to that time of year when water temperatures in the Snake River are starting to drop below 70°F and cold-water releases from Dworshak Dam have been reduced considerably. What this means is the cold-water refuge in the confluence area is starting to diminish which will motivate the fall Chinook salmon that have been congregating there to continue their migration upstream. As such, don't expect the fishery in the confluence area to continue for much longer.

One last thing I want to make you aware of is yesterday (9/24/25) the Corp. of Engineers began some repair work at Lower Granite Dam that seemed to influence fish passage as daily counts of fall Chinook salmon dropped to about 500 fish. I'm not sure how long this will last, but it certainly could influence the fishery in the confluence area if it continues.

Steelhead

Steelhead Returns to the Upper Salmon, Little Salmon, and Snake Rivers

The run of steelhead over Bonneville Dam that are destined for the Upper Salmon, Little Salmon, and Snake rivers is now about 95% complete (as of 9/23/25). This allows us to accurately compare this year's return with past years. The figure below shows how many Idaho hatchery steelhead (based on PIT tags) we estimate will pass over Bonneville Dam this year that are bound for the Upper Salmon, Little Salmon, and Snake rivers in comparison to the previous 15 years.

In this figure, the blue portion of the bars represent fish destined for the upper Salmon River, the green represents fish destined for the Little Salmon River, and the yellow is for Snake River fish. If you add all three of these areas together, it comes to about 28,500 steelhead which is similar to what we observed in 2023 but down from last year. About 65% of these fish are 1-ocean fish (22-26 inches) which is typical for these returns.