The Salt Plains National Wildlife Refuge is part of the United States system of national wildlife refuges. It is located in Alfalfa County in northern Oklahoma, north of Jet (pop. 230), along Great Salt Plains Lake, which is formed by a dam on the Salt Fork of the Arkansas River. The refuge was established March 26, 1930, by executive order of President Herbert Hoover, and contains of protected land as habitat to about 312 species of birds and 30 species of mammals. It was designated a national natural landmark in June 1983. Refuge description The Salt Plains were a favorite hunting ground for American Indians. Bison and other game came to the area to eat the salt and the heavily wooded and well-watered area along the Salt Fork River was like an oasis in the surrounding grassland of the Great Plains. Salt Plains refuge is divided into almost equal areas of nonvegetated salt flat, open water, and vegetated land. Marshes, woods, grasslands, and croplands dot the refuge. Management tools used to enhance the habitat for wildlife include farming, grazing, prescribed burns, construction of ponds, and wetland draining and flooding. The refuge was created to be a resting and breeding ground for migratory waterfowl especially during fall and spring. The entire refuge is designated as critical habitat for the endangered whooping crane, which is mostly seen during fall migration. In addition, the refuge is home to endangered least terns, threatened snowy plovers, threatened bald eagles, and peregrine falcons. Large populations of American white pelicans migrate through between August and September, staying on the Great Salt Plains Reservoir. Great Salt Plains is one of the most important habitats for shorebirds in the Western Hemisphere. Ralstin Island Ralstin Island (closed to the public) is an important rookery in the Great Salt Plains Lake. The island was originally , but has eroded to about . It hosts more than 30,000 birds during breeding season. Over 30 species nest in the colony, including the white-faced ibis, great blue herons, and most notably, the tricolored heron. History of the Great Salt Plains Osage Control of Great Salt Plains According to Historian Louis F. Burns, the Osage Indians used the salt found in the Great Salt Plains to bleach deer-skins and the Great Salt Plains gave the Osages a surplus of salt to trade with other tribes. According to Burns, the Osage were firmly in control of