Deep in Iron Canyon, within Bidwell Park in Chico, a bedrock gorge on Big Chico Creek (Ótakim Séwi) has blocked upstream fish migration for decades. A concrete and rebar fish ladder installed there in 1956 was meant to help, but it has long since stopped functioning, leaving Central Valley Spring-run Chinook Salmon, steelhead, and the creek's native fish community cut off from cold, high-quality habitat further upstream.

CalTrout is working with the Mechoopda Indian Tribe, the City of Chico, the Big Chico Creek Ecological Reserve, and the California Department of Fish and Wildlife, with funding from NOAA, the U.S. Fish and Wildlife Service, California State Parks, and Parks California, to fix that for good. Rather than repairing the old fishway, the project removes its non-functioning components and reconfigures the rock fall itself into a series of natural step-pools that fish can pass through across a wide range of stream flows, an approach that needs no ongoing maintenance and can withstand sediment transport and high-flow events, unlike the structure it replaces. CalTrout used this same passive, natural-channel approach successfully at Eagle Canyon on Battle Creek in 2021.

Instream construction began in spring 2026, with completion expected in 2027. Once finished, the project will reopen 8.5 miles of Big Chico Creek to its full historical distribution of spawning and rearing habitat, giving fish that haven't moved freely through this stretch of creek in decades a clear path upstream, and restoring a piece of the Central Valley's salmon and steelhead recovery that has been missing for nearly 70 years.