The Lower Marais des Cygnes watershed (HUC 10290102) spans 2,549 square miles in eastern Kansas and Missouri. The watershed contains numerous streams, including the Marais des Cygnes River and Osage River, which are characterized by a humid continental climate. The hydrology of the watershed is influenced by seasonal snowpack, with the heaviest snowfall typically occurring in January and February. Low-gradient stream channels and alluvial floodplains are common features of the watershed. Surface water quality is monitored by the state and is generally considered good, though some areas may experience localized contamination. The watershed contains several reservoirs, including Truman Lake and Pomme de Terre Lake, which provide recreational opportunities and support local economies. Current trends suggest that the region will continue to experience warmer temperatures and more frequent extreme weather events in the coming decades.