ESA Status: Threatened – Designated Critical Habitat
The Snake River Basin Distinct Population Segment (DPS) includes all naturally spawned, and some artificial propagation program, anadromous steelhead trout (Oncorhynchus mykiss) originating below impassable barriers in the Snake River basin. Steelhead trout are rainbow, and its subspecies, redband, trout that migrate from the sea up rivers to spawn. Historically, steelhead trout migrated to the Clearwater, Salmon, Weiser, Payette, Boise, Owyhee, Bruneau, and Salmon Falls Creek drainages. However, since the construction of the Hells Canyon Dam complex in the 1950s, many of these populations were eliminated.
The Snake River Basin steelhead trout DPS was first identified as an Evolutionarily Significant Unit (ESU) by the National Marine Fisheries Service (NMFS) in 1997. Near the end of 2005, the NMFS issued a final rule designating Critical Habitat for the Snake River Basin steelhead trout ESU. In 2006, the NMFS officially listed the Snake River Basin DPS of steelhead trout as Threatened on the Endangered Species List (ESA). The most recent Five-Year Status Review of the steelhead trout DPS was completed in 2016 and a Recovery Plan was established a year later in 2017. The main threat the Snake River Basin DPS is habitat loss, impediments, and degradation.