Bringing Back Steelhead to the Potlatch

While surveying the Potlatch River about 10 years ago, the Idaho Fish and Game discovered something surprising - a resilient population of wild steelhead. The Potlatch River is a small, little known river that flows into the Clearwater River about 15 miles upstream of Lewiston, Idaho. Prone to flash floods in spring with sections going almost dry by summer, the Potlatch is hardly a river that one would expect to support any type of a quality fishery - let alone steelhead. Years of habitat degradation in the drainage had taken its toll. Local residents told stories of when their grandfathers caught steelhead in tributaries that are now dry by the end of the summer. Knowing the drainage had the potential to produce more steelhead, Fish and Game and a diverse group of other state, local and federal agencies, as well as local landowners, embarked on a major habitat restoration program in the watershed. This work included improving in-stream and riparian habitat, restoring wetlands, removing migration barriers, removing and repairing problem roads, and a variety of other land management practices to improve stream conditions. To better understand where the steelhead occur, how many there are, and how they respond to various habitat improvement projects, Fish and Game began a steelhead monitoring program nine years ago where adults and juveniles are sampled using fish traps and electrofishing. Each adult and juvenile is tagged with a Passive Integrated Transponder, commonly known as a PIT tag. This glass encapsulated computer chip is about the size of a grain of rice and is automatically detected when the fish passes antennae located along the river and at the dams. Besides providing important information like when the adults and smolts enter or leave certain streams, this information helps to estimate how many adults return to spawn annually, and to evaluate numbers of juveniles that migrate to the ocean each year. From this information, Fish and Game can assess steelhead survival and how well the habitat restoration is working. Much of the monitoring occurs in the East Fork Potlatch River and Big Bear Creek, two of the major steelhead producing drainages in the Potlatch drainage. Since the start of the monitoring, the highest annual adult steelhead estimates have been 140 and 317 fish spawning in the East Fork Potlatch River and Big Bear Creek respectively. In one of the strong run years, it is believed around 1,000 adult steelhead entered the Potlatch River to spawn in the watershed. In 2014, an estimated 8,356 smolts out-migrated from the Big Bear Creek drainage and 11,126 from the East Fork Potlatch River drainage. These estimates are typical and have ranged from 7,000 to 48,000 in the East Fork and 4,000 to 20,000 in Big Bear Creek. Fish and Game will continue to monitor and evaluate the steelhead population as habitat restoration efforts continue. These efforts will help insure the steelhead population thrives for years to come and ultimately provide new fishing opportunities for anglers. To view photographs and to learn more about the project, visit https://fishandgame.idaho.gov/content/article/potlatch-river-steelhead.