 Only Cheyenne, the state capital, is larger.Casper is nicknamed "The Oil City" and has a long history of oil boomtown and cowboy culture, dating back to the development of the nearby Salt Creek Oil Field.In 2010, Casper was named the highest-ranked family-friendly small city in the West, and ranked eighth overall in the nation in "Forbes" magazine's list of "the best small cities to raise a family".