The South Fork Payette watershed (HUC 17050120) covers an area of approximately 1,110 square miles in southwestern Idaho. The hydrology of the watershed is characterized by high mountain peaks, steep canyons, and numerous streams and tributaries that feed into the South Fork of the Payette River. The area experiences significant snowfall in the winter months, which contributes to the watershed's abundant surface water resources. The watershed is home to several large reservoirs, including the Deadwood, Cascade, and Black Canyon Reservoirs, which provide water for irrigation and other uses. In recent years, the region has experienced a trend of decreasing snowpack and earlier snowmelt due to warmer temperatures. This has led to concerns about water availability and the potential for drought in the region. Despite these challenges, the South Fork Payette watershed remains an important resource for the region's economy and ecosystem.