The Upper Yakima Watershed (HUC 17030001) is a large watershed located in central Washington State. It encompasses an area of approximately 3,100 square miles and is characterized by a wide range of hydrologic features, including mountainous terrain, high-elevation forests, and numerous streams and rivers. The watershed is heavily influenced by snowpack, with winter storms providing the majority of its annual precipitation. The Yakima River, the primary surface water feature in the watershed, is fed by numerous tributaries and provides important habitat for a variety of fish and wildlife species. Additionally, the watershed is home to several large reservoirs, including Keechelus, Kachess, and Cle Elum, which serve as important sources of water for irrigation and other uses. In recent years, the watershed has experienced significant changes in temperature and precipitation patterns, with warmer winters and earlier snowmelt being notable trends.