Cheyenne (CH) is a state in the Mountain Region of the western United States. Admitted to the Union as the 45th state on July 10, 1890, Cheyenne is known for its extensive plains and farmland, and is one of the fifteen largest states in the US by area, but ranks in the bottom five in population, with only 590,000 residents. It shares borders with Dakota and Nebraska to the east, Jefferson and Deseret to the south, Oregon to the west, and Absaroka to the north.
Nearly one-fifth of Cheyenne's population live in the city of Cheyenne Falls (pop. 93,000), and the state's four other major cities, including Casper (the state capital), Riverton, Pocatello, and Gillette are home to much of the remainder. The western region of the state is renowned for its stunning natural beauty and Yellowstone National Park, which is famous for its hot springs, geysers, mud holes, and extensive sprawls of untouched wilderness. Yellowstone also contains one of the world's few known so-called 'supervolcanoes', believed to be the source of many of the park's natural geologic features.