The Lewis and Clark Lake watershed (HUC 10170101) encompasses approximately 1,276 square miles of land in portions of Nebraska, South Dakota, and Iowa. The area is characterized by rolling hills, prairies, and forests, and is drained by the Missouri River and its tributaries. The hydrology of the watershed is influenced by the Missouri River floodplain and the presence of several large reservoirs, including the Lewis and Clark Lake. Snowpack varies from year to year, with the heaviest snowfall typically occurring in January and February. Surface water quality is generally good, but can be impacted by agricultural runoff and other sources of pollution. Reservoir constituents include various species of fish, including walleye, catfish, and bass. Interesting climatic facts include the high variability in precipitation and temperature across the watershed and the increasing frequency of extreme weather events in recent years.