The Beaverhead Watershed (HUC 10020002) spans over 5,000 square miles of land area and includes portions of Montana and Idaho. The hydrology of the watershed is dominated by the Beaverhead River, which flows into the Jefferson River and eventually the Missouri River. The region experiences a continental climate with cold winters and warm summers. The watershed is known for its significant snowpack, with the highest elevations receiving over 100 inches of snow annually. Surface water in the watershed is used for agricultural irrigation and recreational activities such as fishing and boating. Reservoirs in the watershed include Clark Canyon Reservoir and Barrett's Diversion Dam. Interesting climatic facts include the occurrence of severe droughts and wildfires, as well as increasing temperatures and decreasing precipitation in recent years, which may have implications for water availability and ecosystem health in the future.