The White Mountain Petroglyphs in the Red Desert north of Rock Springs, Wyo., feature hundreds of images carved into a rock face between 1,000 and 200 years ago. The site is on Bureau of Land Management land, and is open to the public.

As many as half a million people crossed what’s now Wyoming in the mid-19th century before the transcontinental railroad was built. Their trails followed the North Platte and Sweetwater rivers west to South Pass, after which they divided into various routes bound for Oregon, Utah or California. They were making the journey of a lifetime, on routes blazed by Indians and trappers, and then worn deep and wide by thousands of wagons and perhaps millions of draft animals. These trails remain largely unchanged in Wyoming. Their white-topped wagons still hold an important place in the national imagination.

Trail End, the mansion home of cattleman, banker and politician John B. Kendrick, was completed on a hilltop overlooking Sheridan, Wyo. in 1913, 16 months before Kendrick was elected governor. Kendrick later served three terms in the U.S. Senate and died in 1933. The Kendrick family continued to use the house until 1961. In 1968, the Sheridan County Historical Society bought the building, and in 1982 transferred ownership to the state, which operates the 14,000-square-foot mansion now as a state historic site.

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.

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.

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.

Delegates to Wyoming’s Constitutional Convention had to work quickly in 1889 to get a constitution adopted while Congress was still in session. Still, they managed to adopt some innovative ideas, especially in water law. The biggest stumbling block to statehood, in Congressional debate the following year turned out to be whether Wyoming had enough people. It was a close call.

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.

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.

Toomey’s Mills in Newcastle, Wyo., began operations as Newcastle Milling Company and Electrical Light Plant in 1905, producing flour by day and generating electricity at night. In 1919, D. J. Toomey purchased the business and it remained in the family until 1965. In 1974, new owners converted it into a restaurant, the Old Mill Inn. In 1995, current owners, Doug and Larita Brown bought the property, which is listed in the National Register of Historic Places, in 1995.