The Vermillion Watershed covers an area of approximately 1,200 square miles in eastern South Dakota and western Minnesota. The area is characterized by a humid continental climate with cold winters and warm summers. Snowpack is an important component of the hydrology in the watershed, with significant winter precipitation contributing to streamflow during the spring thaw. The surface waters in the watershed are dominated by several small streams and tributaries that feed into the Vermillion River. The Vermillion River flows into the Missouri River, which is an important source of drinking water for the region. Reservoir constituents within the watershed include several small impoundments, which are primarily used for recreation. Interesting climatic trends in the area include an increase in annual average temperature, a decrease in annual average precipitation, and an increase in extreme weather events. These trends are likely to have important implications for water management within the Vermillion Watershed.