There are 13 National Natural Landmarks in South Dakota.
Name Image Date Location County Ownership Description Ancient River Warren Channel Grant mixed- state, private A channel cut by the Ancient River Warren during the Ice Age. Bear Butte Meade mixed- state, tribal, private A cone-shaped mass of igneous rock standing alone above the surrounding plains. Bijou Hills Charles Mix private An excellent example of an erosional remnant of soft clays and shales capped by a channel sandstone and quartzite. Buffalo Slough Lake state Excellent examples of a prairie pothole with native emergent vegetation, and a native bluestem prairie. The Castles Harding federal (Custer National Forest) Steep-walled, flat-topped buttes standing above the surrounding prairie. Cathedral Spires and Limber Pine Natural Area Custer state (Custer State Park) An excellent, rare example of joint-controlled weathering of granite. Cottonwood Slough-Dry Run Roberts mixed- state, private A completely undisturbed wetland complex including potholes, streams, shallow open water, lakes, and marsh. Fort Randall Eagle Roost Gregory federal (Missouri National Recreational River) A prime winter roosting area for bald and golden eagles. Lake Thompson Kingsbury state Contains a large undisturbed and unmanipulated marsh, an outstanding waterfowl breeding and resting area. The Mammoth Site Fall River private One of the largest concentrations of mammoth remains in the United States. Red Lake Brule state One of the largest remaining natural and unmanipulated prairie pothole lakes. Sica Hollow Marshall state Displays many facets of natural history. Snake Butte Jackson tribal (Oglala Sioux) Illustrates one of two types of sand calcite deposits in the world.
See also
List of National Historic Landmarks in South Dakota