As readers of this blog know, spring chinook returns to the Deschutes River have been critically low for many years while fall chinook are doing quite well. Fall chinook spawn in the mainstem of the Deschutes River while spring chinook spawn in tributaries. Major spawning tributaries like the Metolius and Crooked rivers, and their tributaries, were made inaccessible following the construction of the dams that created the Pelton Round Butte complex, leaving lesser tributaries like the Warm Springs river for spawning. The upper basin (above PRB) reintroduction program was intended to provide spring chinook access to their primary historical spawning grounds. The 2026 spring chinook return season is over and I have some data on results. I want to thank the biologists at Portland General Electric for going out of their way to get me this data prior to their discussion at the annual Deschutes Fisheries Workshop which traditionally happens in July.
The first spring chinook was passed into the upper basin on 5/11/2026 after collection at the trap below PRB. The last one was on 9/17/2026. 409 spring chinook were passed. Of those, 383 were excess broodstock and 26 were LM fish. Excess broodstock are spring chinook in excess of what is required for hatchery production at the Round Butte Hatchery at the base of the Round Butte Dam. LM fish are fish raised to smolt size at RBH and then planted in the upper basin. They are marked by clipping their left maxillary bone prior to being planted. These smolts made their way to the Selective Water Withdrawal tower, were trucked around the hydroelectric project, released into the Lower Deschutes, made their way to the ocean, and then came back. No adult spring chinook originating from natural spawning above PRB were captured.
153 of the chinook were released into Lake Billy Chinook and 256 were trucked directly to the Metolius. The Metolius is believed to be the tributary most viable for natural reproduction. 88 of the fish were adult makes, 128 were jacks (juvenile males that can still spawn), 182 were adult females, and 11 were jennies. I did not confirm this, but in the past the juvenile fish were all excess broodstock and I assume the same was the case this year.
70 of the springers were radio tagged. Analysis of their location is ongoing but “many” moved into the Metolius. I assume that final location data will be presented at the next Deschutes Fisheries workshop. Redds have been detected in the Metolius. I was also able to look at the fish count data at Opal Springs Dam from Deschutes Valley Water District, they counted 17 chinook passing through the fish ladder. Of those, 3 were fish passing back down. Perhaps those fish went back into Lake Billy Chinook after spawning, perhaps they just did not like what they found. Note that the automatic fish detection station at Opal Springs had periods of technical difficulties as well as being shut down due to high flows, so all we can really tell from these counts is that the ladder was used by some fish.
The good news is that 26 adult returning LM fish were captured. Last year all of the springers passed into the upper basin were excess hatchery broodstock. The bad news is that only 26 LM fish were captured, far below the goals of the reintroduction project.
See this post for more commentary on last year’s returns. See this post for more on spring chinook status in the Deschutes.
