- Casper is a city located in Natrona County, Wyoming, United States. It is the second-largest city in the state, with a population of approximately 60,000 residents as of 2020. Casper is known for its scenic beauty, outdoor recreational activities, and its economy heavily influenced by the energy industry, particularly oil, gas, and coal. The city offers a variety of cultural attractions, including museums, art galleries, theaters, and annual events like the Central Wyoming Fair and Rodeo. Additionally, Casper is surrounded by natural landmarks like the Casper Mountain and the North Platte River, providing opportunities for hiking, fishing, skiing, and other outdoor pursuits.