Vienna, the trail continues to descend until it reaches Mile 14, where its elevation of is only higher than is its elevation at the trail's origin. After the trail crosses Difficult Run (Mile 14.3), it ascends and descends between additional streams (including Sugarland Run, Broad Run, Beaverdam Run, Goose Creek, Sycolin Creek and Tuscarora Creek) as it travels further northwest in the Piedmont through or near Reston, Herndon, Sterling, Ashburn, and Leesburg. While traveling through Reston, the trail crosses Wiehle Avenue (VA 828), northeast of the Wiehle–Reston East station on Washington Metro's Silver Line. When crossing Tuscarora Creek in Leesburg, the trail's elevation of is only higher than the highest elevation that it reached in Arlington. After crossing that stream, the trail climbs northwest in to reach its highest elevation () while traveling on a bridge carrying VA 9 (Charles Town Pike) over VA 7 near the saddle point of Clarke's Gap in Catoctin Mountain. before this crossing, the trail travels under an old stone arch that formerly carried VA 7 over the W&OD Railroad. The trail then turns west, descends through Paeonian Springs to Hamilton Station and climbs to reach Purcellville. When the trail terminates in Purcellville, its elevation is above sea level. Trail features History When the W&OD Railroad closed in 1968, its wide right-of-way extended from Potomac Yard in Alexandria to the center of Purcellville. Soon after the railroad closed, the Virginia Department of Highways purchased the railroad's property from the line's owner, the Chesapeake and Ohio Railway, with the intent of using a portion of the right-of-way for the construction of I-66. In the same year that the railroad closed, the Virginia Electric and Power Company (VEPCO) (part of which was incorporated into Dominion Virginia Power in 2000) purchased most of the property from the highway department, as the company's electric power transmission lines were travelling within the right-of-way. Trail construction and extension The first portion of the W&OD Trail opened in 1974 within the City of Falls Church under a lease agreement between the City government, the power company and the NVRPA. As the trail proved to be popular, the NVRPA agreed to purchase the right-of-way from the power company on December 19, 1977, and made purchases of it between 1978 and 1982. The power company retained an easement that permitted the company to maintain its lines and to extend them along the right-of-way if