There are three National Natural Landmark sites located within the state of Oklahoma. Natural features represented include the largest inland saline basin in the Central Lowlands biophysiographic province, a deeply eroded box canyon supporting many disjunct mesic plant species, and a classic example of a xeric upland oak-pine forest. Devil’s Canyon and McCurtain County Wilderness Area were both designated in 1974 and the Salt Plains National Wildlife Refuge received recognition as a NNL in 1983. Sites range in size from 160 acres to nearly 32,000 acres. Site ownership for these areas include U.S. Fish and Wildlife Service, county government and a private organization.
Below is a map of sites in Oklahoma.
Please remember, National Natural Landmarks (NNLs) are not national parks. NNL status does not indicate public ownership, and many sites are not open for visitation.