Motoring was an adventure in the second decade of the 20th century, when few roads were paved and travel was often hindered by dust, mud, and snowdrifts, but growing car ownership increased demands for better roads as boosters argued that good roads increased commerce, tourism, and community prosperity. For communities such as Custer, a good road was as important as the railroad. In 1912, businessmen from South Dakota, Minnesota, and Montana formed an organization dedicated to creating a good coast-to-coast road called the Yellowstone Trail, which ultimately evolved into a highway linking Plymouth Rock, Massachusetts, and Seattle, Washington, with a branch from Livingston south to Yellowstone National Park. It was an interconnected chain of county roads marked by chrome yellow signs with arrows, and the Yellowstone Trail Association aggressively promoted it to tourists, sponsored annual Trail Days to keep the road passable, and designated local businessmen along the route as Trail men who helped travelers. In Montana, the Yellowstone Trail extended 800 miles, including branches to Yellowstone Park and other tourist destinations. Initially a dirt road considered slippery in wet weather, it was slowly improved by the Montana Highway Department after World War I, and by 1926 it was officially known as U.S. Highway 10. Montana spent more on improving the Yellowstone Trail than any other state along its route, and today Interstates 94 and 90 parallel much of the old trail.