Mississippi River State Fish and Wildlife Area is a 24,386-acre protected tract in western Illinois along the Mississippi River in Jersey and Calhoun counties. Managed by the Illinois Department of Natural Resources, it is designated as a state fish and wildlife area. The site preserves a substantial expanse of river-oriented habitat and forms part of Illinois’s broader system of public conservation lands, giving it importance as both a protected natural landscape and a component of the state’s conservation network.