Wyoming is a state in the western United States. Most of the state is in the Rocky Mountains, a large mountain range in the United States. Wyoming is the least populated U.S. state with a population of 576,412 people. Its capital and biggest city is Cheyenne. It borders Montana, South Dakota, Nebraska, Utah, Idaho, and Colorado. Wyoming is 97,914 square miles in area, which makes it the 9th largest state in the United States.