From about 1910 to 1960, the National Road revived with the rising popularity of the automobile as reliable cars brought tourist travel within reach of average people. Along these Allegheny ridgetops, “waysiders” built hotels, garages, and roadhouses to serve “tin-can tourists,” and their businesses prospered or failed according to traffic on U.S. Route 40, the old National Road. Their success proved short-lived as continued road improvements and the eventual construction of I-68 led nearly all of these mountain-top service centers to close. At the foot of Martin Mountain, the road touched the lower edge of Pleasant Valley and passed Clover Hill Farm, whose site is now occupied by Rocky Gap State Park. For travelers on the old National Road, a milestone here marked six miles to Cumberland, Maryland, a welcome sign after difficult terrain. The tradition of mile markers dated back more than 2,000 years to the roadbuilders of the Roman Empire, continued into early 19th-century America, and became an important part of travel on the National Road, where progress was often only a few miles a day. Beginning in Cumberland, cast-iron obelisks marked the miles to Wheeling, West Virginia, the original terminus of the National Road.