Gillette, Wyoming, established in 1891, is the county seat and largest incorporated city in Campbell County. It was named after Edward Gillette, a surveyor for the Burlington and Missouri railroad who, by all accounts, saved the company five miles of track and thirty bridges with his surveying skills. Located on I-90 just 60 miles from the Black Hills or the Bighorn Mountains, Gillette was first recognized as a ranch and stock yard community. Today, with a population of approximately 22,000, it is known for its prominence in the mineral industry and is considered the Energy Capital of the Nation.

There are 15 active coal mines in the area; five of which are the largest in the world, producing twenty five percent of the nation's coal. Summer coal mine tours are available Monday through Friday that give a firsthand view of the house-size mining equipment, extrication and shipment of coal, and acres of land reclaimed to its natural state.