Two Top and Big Top Mesa
Two Top and Big Top Mesa are two adjacent mesas about apart in western North Dakota. They were declared National Natural Landmarks in 1965. The tops of the mesas are rare examples of undisturbed grassland which have never been grazed or cultivated. They are located in or around the Little Missouri National Grasslands. Geology. Big Top mesa is approximately while Two Top is around . They rise about above the badlands. They are made of sandstone, Morton silt loam and clay.