Construction of Buffalo Bill Dam, completed in 1910 six miles west of Cody, Wyoming, was the key that opened about 90,000 acres in northwestern Wyoming to irrigated farming. Its construction was slowed by engineering difficulties and labor strife, but when it was finished stood as an engineering marvel, one of the first concrete arch dams built in the United States and the tallest dam in the world at the time.

Notorious outlaw Butch Cassidy and his Wild Bunch frequently crossed and hid out in Wyoming when on the run from the law. Cassidy’s 18-month incarceration at the Wyoming State Prison in Laramie, 1894-1896, is a definite fact. Other than that, stories place him and his gang all over the map, from Sundance to Brown’s Hole, and Powder Wash near Baggs to Hole in the Wall near Kaycee. Stories persist as well that Cassidy returned to Wyoming decades after his reported death in Bolivia in 1908, but no hard evidence has yet turned up.

Was she a hard-drinking, swashbuckling mule skinner and Indian fighter? Or an alcoholic prostitute, stuck in menial jobs in a life both dreary and mundane? Calamity Jane's life is two stories: the facts of her biography, and the romantic tales that came to comprise the Calamity Jane legend.

The Carbon cemetery has been in use since 1868, when the town of Carbon was founded next to coal mines on the Union Pacific Railroad. The town has long been a ghost town, but interest in the cemetery revived in 2002, when a local association began refurbishing it and researching the lives of the people buried there.

Beautiful Carbon County in south-central Wyoming was established in 1868 and named for its coal. Since fur-trade days, through coal, copper, cattle, sheep, uranium, coal again, natural gas and wind power, booms, busts, and new booms have dominated the economy. The Union Pacific Railroad has by contrast offered a steadying influence, as has the state prison in Rawlins, the county seat. And the North Platte River, locals say, offers the best trout fishing in the world.

Founded in 1868, the short-lived town of Carbon provided crucial coal supplies for the Union Pacific Railroad. Its rough reputation was boosted in 1881, when a mob of miners pulled Dutch Charley Burris, accused of the murder of a popular lawman, from a train and hanged him from a telegraph pole. Many Finnish men worked in the coal mines until 1902, when the mines closed. Today, there are only a few ruins to mark the site, but the Carbon Cemetery has been recently refurbished and is still being used.

Casper’s Odd Fellows Building, constructed in 1952, reflects the modern-style architecture that was popular during the postwar era and serves as a reminder of the community development, planning and the social history of the time. This structure is named on the National Register of Historic Places.

Though the site was an important river crossing on the early frontier, the town of Casper did not begin until 1888, when the Fremont, Elkhorn & Missouri Valley Railroad reached the area. The town immediately became an important shipping point for cattle and wool. The first oil refinery was built in 1895 to process crude oil from the Salt Creek Oil Field, 40 miles to the north. The first true oil boom began after 1910 and lasted through the mid 1920s, and the town’s fortunes have been closely connected to the energy business ever since. In 2010 the city’s population passed 55,000. Casper continues as a retail, medical and energy-industry service hub.

The scenic Bighorn Basin and world-class fishing opportunities on the Bighorn River have made Big Horn County, Wyo., a tourist destination, but the area is also rich in oil and natural gas—and history. People have lived in the area since ancient times, as evidenced by the Medicine Wheel near the county’s northern corer. Ranch families still raise cattle and sheep, and farm families still raise sugar beets as they have for more than a century.

Bessemer, Wyo., on the North Platte River west of Casper, was founded in 1888 but disappeared after failing to win the status of county seat of the brand-new Natrona County in 1890.