History of Sideling Hill in Timeline

By Popular Timelines Editorial Team · Updated: November 29, 2025

Sideling Hill is a prominent mountain ridge in the Appalachian Mountains, traversing western Maryland, Pennsylvania, and West Virginia. Characterized by its steep and narrow formation within the Ridge-and-Valley province, its highest elevation reaches 2,310 feet at Fisher Point in Fulton County, Pennsylvania. The ridge is a notable geographical feature of the region.

1911: Locomotive Derailment

In 1911, ice inside the East Broad Top Railroad tunnel caused the brand new locomotive #12 to derail its pilot axle inside the tunnel then derail the entire locomotive at the Kimmel switch just beyond the tunnel.

1919: North Portal Replaced

In 1919, the north portal of the East Broad Top Railroad tunnel through Sideling Hill was replaced with a concrete portal, replacing the original stone portal.

1940: Turnpike Opening

In 1940, the Sideling Hill Tunnel, the longest of the seven original turnpike tunnels at 6,782 feet long, was opened as part of the Pennsylvania Turnpike.

1956: Railroad Ceases Operations

In 1956, the East Broad Top Railroad ceased operations, thus ending the service of the Sideling Hill tunnel. The track is still in place through the tunnel, although not serviceable.

November 26, 1968: Sideling Hill Bypass Opens

On November 26, 1968, the Sideling Hill bypass of the Pennsylvania Turnpike (Interstate 76) opened at a cost of $17,203,000. This bypassed the two-lane Sideling Hill Tunnel and the nearby Rays Hill Tunnel.

1968: Tunnel Usage Ends

In 1968, the Sideling Hill Tunnel was no longer used as part of the Pennsylvania Turnpike due to increasing traffic. A new six-lane highway was built to bypass the tunnel.

August 1984: Blasting Completed

In August 1984, blasting was completed for the Sideling Hill Road Cut on I-68 and US 40. The road cut is a 340-foot-deep notch excavated from the ridge of Sideling Hill.

1991: Sideling Hill Exhibit Center Opens

In 1991, the Sideling Hill Exhibit Center, a four-level geological museum and travel information center, opened to the public.

1992: Clinton-Gore Bus Tour Stop

In 1992, the rest area next to Sideling Hill was a stop on Bill Clinton and Al Gore's post-convention bus tour.

2001: Tunnel Sold

In 2001, the Sideling Hill Tunnel was sold for $1 to the Southern Alleghenies Conservancy, which now operates it as a bike trail.

August 15, 2009: Sideling Hill Exhibit Center Closes

On August 15, 2009, the Sideling Hill Exhibit Center was closed due to state budget cuts. The closure was part of a $280 million budget reduction package.

October 9, 2015: Welcome Center Reopens

On October 9, 2015, the former exhibit center building was reopened as a welcome center. Only part of the facility is open, with the former exhibit center exhibits remaining at the Hancock Museum.