Idaho coho

Name: Coho passage at Lower Granite Dam
Creator: U.S. Army Corps of Engineers

A reintroduced run counted at the dam since the mid 2000s, read by the Clearwater.

Crosses the dam from September, peaks in October and runs into November. More about the species.

Counts through Thu, Oct 22 · yesterdayCurrent

The Corps posts each day's count a day late. Next update tomorrow around noon Mountain.

Right now

Lower Granite is the last dam below Idaho. Fish counted there are headed for the Snake, Clearwater and Salmon systems.

Coho · Lower Granite Dam

Well below typical

The run is tapering off

Counted Oct 22

7-day average

Percentile for the date

0th

This run so far

3,671

Passage over the last three days is well below typical for late October (0th percentile) and easing.

3,671 coho have passed Lower Granite this year. In a typical year about 75 percent of the run is through by October 22, and passage peaks around October 12.

On pace for roughly 4,200 to 6,900 fish, against a typical 8,600.

Passage over time

Bars are the day's count at Lower Granite through Oct 22. The dashed line is what the date usually brings, the ten-year median.

When they reach this water

Antennas in the water read tagged fish as they swim past. A best guess is our estimate of the peak; fish seen are dates real fish were actually recorded. Each spot below says whether it sits on this river or on a tributary.

No arrival timing for the Coho yet: no PIT-tag array reads this stretch, so the run status above is Lower Granite Dam's.

Arrival timing from PIT-tag detections via PTAGIS and Columbia River DART; tagged fish are a sample of the run, never a count.

Counts by the U.S. Army Corps of Engineers via Columbia River DART.

The season

When coho usually cross Lower Granite, across the whole run-year, and where this year sits against it.

The dashed line is what the date usually brings at Lower Granite, the ten-year median. The solid line is this run-year so far. Passage usually peaks around Oct 8.

Past seasons

Complete run-years at Lower Granite, newest first. The run-year in progress is left out: a season still being counted is not a season total.

Coho totals by run-year at Lower Granite Dam
Run-year	Counted at Lower Granite
2025	9,051
2024	10,346
2023	14,326
2022	19,259
2021	24,226
2020	7,798
2019	7,683
2018	2,040
2017	8,181
2016	2,843

Where they go in Idaho

The corridor waters whose pages read a coho run.

Clearwater River