The 100-foot-wide Washington & Old Dominion Railroad Regional Park features a 45-mile asphalt trail for walking, running, skating, bicycling, and other activities and a 33-mile parallel gravel bridle path for horseback riding and hiking. The trail traverses the Piedmont between the Potomac River and the Blue Ridge Mountains, creating a recreation corridor extending from the Virginia suburb of Arlington to the farming areas of western Loudoun County. It takes its name from the railroad whose trains ran along this right-of-way from 1859 until 1968. Never very successful, the railroad declined more quickly as the road system improved and the number of motor vehicles increased.