The Willow Creek drainage in Idaho is one of 35 major drainages managed by the Idaho Department of Fish and Game, representing a significant component of the state's diverse aquatic ecosystems. Located within Elmore County as a tributary of the South Fork Boise River, Willow Creek extends 19.0 miles in length and serves as an important habitat for both native and introduced fish species. The drainage has experienced various management interventions over the years, including habitat connectivity improvements for Yellowstone Cutthroat Trout through habitat improvement projects and barrier removals. The creek system demonstrates the complex interplay between native species conservation and fisheries management that characterizes much of Idaho's aquatic resources.