The Madison Watershed (HUC 10020007) is located in the Rocky Mountains of western Montana and includes parts of Yellowstone National Park. The watershed covers an area of approximately 9,700 square miles with elevations ranging from 4,000 to over 11,000 feet. The hydrology of the watershed is dominated by snowmelt, with the majority of precipitation falling as snow. The mountainous terrain also contributes to rapid runoff and erosion. The watershed contains several large reservoirs including Hebgen Lake, which was formed by the 1959 Hebgen Lake earthquake. The reservoirs are important for water supply, recreation, and power generation. The Madison River is the primary surface water source in the watershed and is a popular destination for fishing and rafting. Climate trends in the Madison Watershed include increasing temperatures and changes in precipitation patterns. Snowpack levels have been decreasing, leading to concerns about water availability and wildfire risk. The watershed is also experiencing more frequent and severe droughts. These changes have implications for water management, recreation, and ecosystem health in the area.