Clackamas Fish Runs
Trends and timing of fish migration on the Clackamas River
The Clackamas River is home to migrating salmon and steelhead virtually year-round. The chart shows typical migration patterns and the months when runs peak — the best time to schedule a fishing trip or go out salmon watching on the Clackamas. For up-to-date numbers, see Daily Fish Counts.
Summer steelhead were first introduced to the Clackamas River in 1970. While a few fish enter the river as early as February, good numbers are not observed until mid-April. They spawn in January and February the following year.
About 85 percent return after two years in the ocean (“two-salt fish”) and average 7 to 10 pounds. The other 15 percent return after either one or three years in the ocean.
In decades past, summer steelhead smolts were released upstream of North Fork Dam. The adults entered the North Fork fish ladder adult fish trap and were passed upstream.
In recent years, summer steelhead have been acclimated or stocked in the lower river which has significantly reduced the number of adults returning to the North Fork fish trap. In addition, summer steelhead have not been passed upstream of North Fork dam since 1999.
The chart below shows only the North Fork fish trap counts; it does not reflect the total summer steelhead returns to the lower Clackamas.
There are two stocks of winter steelhead in the Clackamas. The early run is supported by hatchery releases made in Eagle Creek by the U.S. Fish and Wildlife Service at the Eagle Creek Fish Hatchery. These fish are released below River Mill Dam so as not to interfere with the native winter steelhead that spawn mainly above North Fork Dam.
Early run winter fish begin to enter the Clackamas in November with most of them spawning in tributaries below River Mill Dam in January and February. There is some natural reproduction, particularly in Clear Creek, Eagle Creek and Deep Creek.
The late run of wild steelhead tend to be slightly larger than the early run fish. They begin to enter the river in January, with peak numbers generally observed in March. Migration over North Fork Dam is mostly in April and May, with fish spawning from late March to mid-June. Through support by PGE, a wild brood stock program was initiated, so this stock now provides expanded fishing opportunities in the lower river.
The Clackamas has two stocks of coho salmon. The introduced early-run fish begin to enter the river in August, spawning in October and early November. Most of these fish are 5 to 10 pounds, with the hatchery component bound for Eagle Creek National Fish Hatchery. There is good natural reproduction in lower river tributaries and in the upper Clackamas upstream North Fork Dam.
The late run coho are the endemic stock to the Clackamas River. While most of them spawn above North Fork Dam, there is a some reproduction in the lower river. These fish are larger than the early run coho, averaging 8 to 12 pounds, with some up to 16 pounds. They enter the Clackamas from November through January and spawn from January to April.
Historically, the Clackamas River has produced large numbers of spring Chinook salmon. Wild populations declined from commercial fishing and from the inability to reach spawning grounds due to egg-taking operations and the failure of the Cazadero Dam fish ladder.
From 1917 to 1939, Chinook were trapped at the Cazadero and River Mill dams to be used for hatchery brood stock. The Cazadero fish ladder failed in 1917 and was not repaired until 1939. But after the reconstruction of the fish ladder, the remnant population from the lower river seeded the upper Clackamas.
More recently, the Clackamas spring Chinook were augmented with Willamette stock Chinook, which have been released in the basin since the late 1950s.
In 1980 the first adults began returning to the newly completed Clackamas hatchery at McIver Park. This hatchery, which is partially funded by PGE, the State of Oregon, the City of Portland and the National Marine Fisheries Service, currently produces about 1.7 million Chinook smolts each year, of which 1.2 million go into the Clackamas River.
Spawning in the Clackamas River has been on the rise since 1980. The increase in spawning is closely associated with increased returns of adults to the Clackamas Hatchery. A majority of hatchery-produced fish return to the river after two or three years in the ocean. Two-salt fish generally weigh 9 to 15 pounds, while three-salt fish weigh 17 to 25 pounds.
Fall chinook salmon were native to the Clackamas. Present-day runs are believed to be fish of the tule strain. Fall chinook enter the Clackamas and spawn in August and September. The majority of the spawning is in the lower river downstream of River Mill Dam. Fall chinook have not been stocked in the Clackamas since 1971.
Sea-run cutthroat trout
Sea-run cutthroat trout in the Clackamas are all wild fish. Entering the river in September and October, they average 12 to 18 inches in length and are found in the larger tributaries downstream of River Mill Dam.