Spring Mill State Park is a 1,358-acre state park in the state of Indiana. The park is located to the south of Bloomington, about 3 miles east of the city of Mitchell on Indiana Highway 60. It contains a settler's village, the Gus Grissom Memorial, a nature center, and campgrounds. The park is located on the Mitchell Karst Plain, which allowed the park's caves and sinkholes to form in the limestone. The caves include Bronson Cave, Twin Caves, Shawnee Cave, Hamer Cave, and others.