This project replaced a severely undersized, failing private road culvert on Upper Green Valley Creek — a Russian River tributary in Sonoma County — with a 15-foot bottomless arch culvert and a 157-foot step-pool roughened channel with boulder weirs for grade control. The culvert had blocked coho access under all flow conditions. The project opened 0.9 miles of spawning and rearing habitat, and post-construction surveys detected 136 steelhead young-of-year upstream of the site, benefiting federally endangered Central California Coast coho salmon and threatened steelhead.