Wyoming is a state in the Western United States. The majority of the state is dominated by the mountain ranges and rangelands of the Rocky Mountain West, while the easternmost section of the state includes part of a high elevation prairie region known as the High Plains. While the tenth largest U.S. state by area, Wyoming is the least populous, with a U.S. Census estimated population of 544,270 in 2009. This is a 5.9% increase since 2000. The capital and the most populous city of Wyoming is Cheyenne.