Scott Bar Fish Passage Project

Mill Creek is a small stream, but its role in the Scott River watershed is outsized: as the lowermost tributary to a river that consistently produces the largest wild coho salmon returns in California, Mill Creek's spawning grounds matter far more to the regional fishery than its size would suggest. For decades, though, fish couldn't reach them. A road crossing 200 feet upstream from the creek's mouth completely blocked passage, and just downstream, a steep bedrock cascade at the confluence with the Scott River was passable only during the highest flows of the year, a legacy in part of habitat degradation from early 1900s hydraulic gold mining that reshaped the channel. Together, these two barriers cut off roughly three miles of cold-water spawning and rearing habitat that hadn't been fully accessible to anadromous fish since the 1980s.

CalTrout worked with the California Department of Fish and Wildlife, the Karuk Tribe, the Siskiyou Resource Conservation District, Siskiyou County, and private landowners to fix both problems at once: removing the old road crossing entirely and replacing it with a channel-spanning bridge, then re-profiling the confluence from a steep cascade into a lower-slope channel that fish can navigate even during typical flows. Construction ran from July 2023 through completion in December 2023, restoring passage to Mill Creek's full three miles of habitat for the first time in nearly four decades. The timing mattered: this stretch of the Scott River has faced significant drought-related flow reductions in recent years, making every accessible cold-water refuge more valuable to the fish that depend on it. Funded by the U.S. Fish and Wildlife Service, the Wildlife Conservation Board, and CDFW's Fisheries Restoration Grant Program, the project is now in a monitoring phase running to track how quickly fish recolonize the newly reopened habitat.