Several excellent museums in Casper illuminate central Wyoming’s pioneer and natural history. The state’s second-largest city, it’s also one of the oldest. Some of the first white people to venture across Wyoming spent the winter here in 1811, on their way east from Fort Astoria in Oregon. Although they didn’t stay, they helped to forge several pioneer trails that crossed the North Platte River near present-day Casper. A permanent settlement eventually arose, and was named for Lieutenant Caspar Collins; the spelling error occurred early on, and it stuck. The town has grown largely as a result of oil and gas exploration, and sheep and cattle ranchers run their stock on lands all around the city.