Different evidence than the rest of this site. The
Cowlitz enters the Columbia below Bonneville, so none of our PIT corridor
math applies here. Everything on this page is a direct count or a published
agency series. No tags, no model, no projection.
Separator, last week
161
summer-run steelhead · report August 24, 2026
Upper Cowlitz + Cispus spawners
439
2025 return, WDFW indicator series
Lower Cowlitz spawners
476
2023 return (series runs 2013–2023)
Weir fish unmarked
89%
of 2,810 steelhead handled at the four
lower-trib weirs since 2011
Three decades of winter fish
The winter run is the wild story here. Fish bound above the dams are
trucked from the separator to the upper Cowlitz and the Cispus; the state has
counted those spawners every year since 1997. The lower-river population gets
its own estimate from weir counts on Delameter, Ostrander, Olequa and Lacamas
creeks. Both series are below their early peaks, and the hatchery share of the
spawning grounds is a management fight that shows up in the gap between the
solid and dotted lines.
WDFW Salmonid Population Indicators, pulled from the
state open-data service. All-spawner and natural-origin series exclude jacks.
When the winter run arrives
The weirs put dates on individual fish. Winter steelhead enter the lower
tributaries from December into May and peak in late winter, and about nine in
ten carry no fin clip. This is the closest thing the lower Columbia has to
the arrival curves our detector pages draw upstream.
WDFW and Tacoma Power weir records, individual live
winter-run fish, 2011–2026. Kelts and carcasses excluded from the
timing count.
Where these numbers come from
Sources on disk: WDFW SPI series 1997–2025;
weir records 2011–2026; Tacoma weekly reports, live archive;
FERC P-2016 annual passage reports 2005–2025 (list enumerated, two
fetched); WDFW sport catch reports 1994–2021, punch cards to 1962;
historical stock tables 1977–2004. Updated 5 September 2026.