Flint Hills National Wildlife Refuge (NWR) was established in 1966 as an "overlay project" on a U.S. Army Corps of Engineers flood control reservoir (John Redmond Reservoir) to provide habitat for migrating and wintering waterfowl. Its 18,463 acres provide a diverse habitat and are a haven for an assortment of mammals, birds, reptiles, amphibian, and insects.

Located in east central Kansas, Flint Hills NWR lies in the broad, flat, Neosho River Valley.  The refuge is located in the tallgrass prairie region of the country and is named for the gently rolling, fossil-studded hills found to the west of the refuge. These hills were laid down when seas blanketed the area 250 million years ago. 

The Neosho and Cottonwood Rivers provide most of the water for the refuge, which is located at the upstream end of John Redmond Reservoir. Refuge habitats include wetlands, bottomland hardwood forests, grasslands, riparian areas, and agricultural lands.