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.