Most of the crest of Sideling Hill is forested, primarily with various deciduous tree species such as oaks (Quercus) and hickories (Carya), along with occasional evergreen pines (Pinus).
Completed at a cost of $17,203,000, the Sideling Hill bypass opened on November 26, 1968, and the former alignment through the tunnels became known as the Abandoned Pennsylvania Turnpike.
A rest area next to the ridge was a stop on Bill Clinton and Al Gore's post-convention bus tour in 1992.
[citation needed] In 2001, the Sideling Hill Tunnel was sold to the Southern Alleghenies Conservancy for $1, which now operates it as a bike trail.
[4] It is notable as an impressive man-made mountain pass, visible from miles away, and is considered to be one of the best rock exposures in Maryland and the entire northeastern United States.
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.
A highway rest stop, located near the eastern side of the Sideling Hill Road Cut on I-68 west of Hancock, includes a pedestrian bridge crossing I-68, connecting the eastbound and westbound rest areas and offering views of the cut, in which stopping is prohibited.
[8] Before construction of I-68, US 40 (now US 40 Scenic), the National Road, crossed Sideling Hill with a steep grade on each side and a sharp hairpin turn at the crest of the mountain.
The water gap cut through Sideling Hill by the Potomac River southwest (upstream) of Hancock, Maryland, provides a low-level crossing of the ridge for the CSX Railroad, formerly the main line of the Baltimore and Ohio (B&O) Railroad, on the southern (West Virginia) side of the river, and on the northern (Maryland) side, the former Chesapeake and Ohio Canal, now a national historical park, and the former Western Maryland Railroad (now a rail trail).