About the data

Where the numbers come from

Every count on this site is a U.S. Army Corps of Engineers dam count, republished by the Fish Passage Center (FPC) in Portland — the public source the Corps itself points to for its fish counts. Trained counters watch the fish ladders at each dam and tally every salmon and steelhead by species.

How a dam count works: in the counting season (April 1 – October 31) the ladders are watched 16 hours a day, 50 minutes of every hour, and the day count is the counted fish expanded by 1.2 for the uncounted minutes. A day count is therefore an expanded estimate, not an exact tally — the same honesty label this family of sites puts on sonar counts in Alaska. In winter the Corps counts from video on a delayed schedule; those winter counts are not included here, so every dam total on this site is the April 1 – October 31 season. A day with no count in the file is never treated as zero.

The comparison: each run is set against its own 10-year average — the final counts of 2016–2025 and the average daily curve across those seasons. The 10-year average for the date is the standard metric in Columbia River fish management.

Forecasts are not goals: there are no escapement goals for dam counts — goals are set for fish that reach the spawning grounds, and a dam tally is passage, not escapement. Where managers publish a preseason run forecast that maps to a counter (the Joint Staff Report forecasts, shown at Bonneville), the page shows it labeled FORECAST: a forecast for the whole run returning to the river, offered as context for the passage count — never as a goal the count is graded against.

Coverage — deliberately the majors

This site covers the eight U.S. Army Corps of Engineers dams with fish ladders on the Columbia and Snake rivers — the counted runs at Bonneville, The Dalles, John Day and McNary on the Columbia, and Ice Harbor, Lower Monumental, Little Goose and Lower Granite on the Snake. These are the counters people look for: every salmon and steelhead heading for the upper Columbia, the Snake and their tributaries passes one of them.

Not here: the mid-Columbia PUD dams above McNary (Priest Rapids, Wanapum, Rock Island, Rocky Reach, Wells), whose counts are published by Grant and Chelan PUDs and WDFW through other systems; tributary weirs, traps and spawning surveys; and Willamette Falls, which is on the Oregon sister site. None of that is missing by accident — this is the short list.

What this site is not

Counts are observations of fish that have already passed a dam — they are not forecasts, and the comparisons are historical context, not predictions. Nothing here is a fishing regulation or an emergency order. For seasons, regulations and management decisions, go to WDFW, ODFW or the Corps' district pages directly.

Dam locations on the map are the published dam sites — for orientation, not navigation.

The family

Sister sites: Alaska Salmon Counts and Oregon Salmon Counts — same idea, same honest labels.

Questions or corrections: info@washingtonsalmoncounts.com