Rock Springs Conservation Area, about four miles southwest of Decatur, Illinois, preserves 1,300 acres along the Sangamon River as Macon County’s largest single parcel of parkland. Centered on the Rock Spring Nature Center and named for a spring flowing from sandstone bluffs, the area includes wetlands, wooded low bluffs, restored tallgrass prairie, and about six miles of trails. Long before preservation, the spring was a meeting place for local Native Americans, and in 1915 and 1916 its water was bottled for local sale. Nearby Miller’s Mill recalls the site’s agricultural past. The protected landscape emerged from early twentieth-century planning tied to Decatur’s expansion and sewage works.