Washington & Old Dominion Railroad Regional Park

Washington & Old Dominion Railroad Trail
Stone arch at Clarks Gap, August 2008
Length	44.7 mi (71.9 km)
Location	Virginia, United States
Trailheads	East: Shirlington in Arlington County West: Purcellville in Loudoun County
Use	Biking Horseback riding Running Hiking
Elevation
Elevation change	469 ft (143 m)
Highest point	Clarks Gap, 610 ft (190 m)
Lowest point	Shirlington, 141 ft (43 m)
Hiking details
Trail difficulty	Easy
Season	All

The Washington & Old Dominion Railroad Regional Park is a linear regional park in Northern Virginia. The park's primary feature is the Washington & Old Dominion Railroad Trail (abbreviated as W&OD Trail), an asphalt-surfaced paved rail trail that runs through densely populated urban and suburban communities as well as through rural areas. Most of the trail travels on top of the rail bed of the former Washington and Old Dominion Railroad, which closed in 1968.

Although the park is 44.8 miles (72.1 km) long, it is only about 100 feet (30 m) wide. The rail trail is approximately 10 feet (3.0 m) wide through much of its length and is suitable for walking, running, cycling, and roller skating. A crushed bluestone surfaced bridle path travels near the paved trail in the park's most westerly 32 miles (51 km).

NOVA Parks (formerly named the Northern Virginia Regional Park Authority (NVRPA)) administers and maintains the park and its trails. NOVA Parks keeps most of the parkland surrounding the trails in a natural state. The park authority has placed alongside the paved trail a series of mile markers and a number of interpretative exhibits that describe the historic and natural features of the park (see Washington and Old Dominion Railroad Stations for locations of historical markers near the W&OD Trail).

The headquarters office of the park is near the east side of the trail at Smith's Switch Road in Ashburn. A park rest stop is adjacent to the trail near the park's headquarters.