About
South Fork Boise River, Idaho — 1951 Anderson Ranch Dam, Tallest. Anderson Ranch Dam releases create 65 miles of consistent whitewater through Elmore and Boise counties, with flows averaging 1,200 CFS and optimal paddling between 500–3,000 CFS. The South Fork Boise River runs hardest from Anderson Ranch Dam to Danskin, where Class III–IV drops provide the technical whitewater that defines this run. Below Danskin to Neal Bridge, the gradient eases to Class II–III intermediate water, while the final stretch from Neal Bridge to Arrowrock Reservoir mellows to Class II floats. Dam-controlled releases since 2015 have supported a regional whitewater economy, with Idaho River Sports among the outfitters running commercial trips. The Shoshone-Bannock considered the broader Boise River Basin part of their traditional territory. Trout Unlimited has designated conservation priority sections within the Boise National Forest corridor. Gauge 13173630 tracks the releases that make this system reliable when natural snowpack rivers elsewhere run low.
River conditions are community-verified. CFS ranges, difficulty ratings, and access points may not reflect every flow level or seasonal change. Always check current conditions, scout unfamiliar rapids, and paddle within your skill level.