Sideling Hill

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Sideling Hill
Sideling Hill road cut - one of the best rock exposures in Maryland and indeed in the entire northeastern United States."--R.D. Conkwright^[1] Alternate view.
Elevation	2,301 feet (616 m)
Location	West Virginia, Maryland, and Pennsylvania, USA
Range	Ridge-and-valley Appalachians
Coordinates	39°43′09.08″N, 78°17′01.41″W
Topo map	USGS Paw Paw

Sideling Hill is part of the Allegheny Mountains of the Appalachian Mountain Range. (Also considered part of the Ridge-and-valley Appalachians). It traverses West Virginia, Maryland and Pennsylvania and rises to its highest elevation of 2,301 feet (616 m) in Fulton County, Pennsylvania^{[citation needed]}.

1 Road cut
2 Tunnel
3 Notes
4 External links

[edit] Road cut

The Sideling Hill road cut seen from Interstate 70

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^[1] 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.

[edit] Tunnel

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 western portal of the now-abandoned Sideling Hill Tunnel, along the mainline of the Pennsylvania Turnpike.

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 sold to the Southern Alleghenies Conservancy for $1, which now operates it as a bike trail.