Toadstool Geologic Park in far northwestern Nebraska is a protected area within the Oglala National Grassland, operated by the United States Forest Service. Known for its stark badlands terrain, it features eroded rock and earth and unusual formations with broad caps and narrow bases. The park also preserves visible fossils, including remains of prehistoric animals such as entelodonts and hyaenodons, giving it paleontological importance as well as striking scenery. A reconstructed sod house adds a human element. A 1-mile loop trail passes through the main geologic area, and the Bison Trail extends 3 miles to the Hudson-Meng Bison Kill.