Sideling Hill is part of the Appalachian Mountains, specifically the Ridge-and-valley Appalachians. It crosses West Virginia, Maryland and Pennsylvania. It rises to its highest elevation of 2,021 feet (616 m) in Morgan County, West Virginia.

Road Cut

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The Sideling Hill road cut is a 340-foot deep road cut where Interstate 68 cuts through Sideling Hill, about 6 miles west of Hancock in Washington County, Maryland. It is notable as an impressive man-made mountain pass, visible from miles away and one of the best rock exposures in Maryland and indeed in the entire northeastern United States. Almost 810 feet of strata in a tightly folded syncline are exposed in this road cut. Although other exposures may surpass Sideling Hill in either thickness of exposed strata or in quality of geologic structure, few can equal its combination of both. There is an Exhibit Center to help provide the public with a better understanding of the geology of the cut. A pedestrian walkway bridge crosses I-68 for better access to the cut, along with a picnic area and rest area facilities.

Tunnel

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A tunnel through Sideling Hill is currently in its third phase of life. In the 1880s, a tunnel was partially bored through the mountain near Breezewood, Pennsylvania by the South Pennsylvania Railroad. The railroad project ceased, and the tunnel was left abandoned. When the Pennsylvania Turnpike Commission began constructing the Pennsylvania Turnpike on the right-of-way of the old South Pennsylvania Railroad in the 1930s, the tunnel was completed.

The tunnel, which, at 6,782 feet, was the longest of the seven original turnpike tunnels, was used from the Turnpike's opening in 1940 until 1968. Due to increasing traffic on the highway, the turnpike commission began upgrading all of its two-lane tunnels. This project involved constructing twin bores for tunnels through the Allegheny, Tuscarora, Kittatinny, and Blue mountains. Tunnels under Laurel Hill, Rays Hill, and Sideling Hill were bypassed with new, four-lane highways climbing the adjacent hills. The Sideling Hill bypass, completed at a cost of $17,203,000, opened on November 26, 1968, bypassing the Sideling Hill tunnel and the nearby Rays Hill tunnel. The tunnels, along with connecting segments of four-lane highway, were used for many years as a testing facility for new highway technologies. In 2001, the tunnel was donated to the Southern Alleghenies Conservancy, which now operates it as a bike trail.

External links

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• Geology of the Sideling Hill road cut, by Maryland Geological Survey
• Sideling Hill Exhibit Center

Hampshire County, West Virginia | Morgan County, West Virginia | Washington County, Maryland | Mountains of West Virginia