The first section of the GAP—9 mi (14 km) near Ohiopyle—opened in 1986.[3] The 9-mile (14 km) section between Woodcock Hollow and Cumberland opened on December 13, 2006.[4] The GAP was completed in 2013 when the section between West Homestead and Point State Park in Pittsburgh opened.[5] The completion project was named The Point Made, reflecting the fact that it was now possible to reach Point State Park from Washington, D.C. Celebrations took place on June 15, 2013. With its opening, Pennsylvania became the state with the most rail trails—900 mi (1,400 km), with 1,100 mi (1,800 km) more under development.[6]
The overall construction cost for the GAP was $80 million.[7]
The Allegheny Trail Alliance (ATA) was founded in 1995 as an umbrella organization for the GAP's seven trail organizations, which include Friends of the Riverfront, Steel Valley Trail, Regional Trail Corporation, Ohiopyle State Park, and Mountain Maryland Trails. Each organization maintains a particular section of the GAP. The ATA was later renamed The Great Allegheny Passage Conservancy.
The original name for the GAP was Cumberland and Pittsburgh Trail. Great Allegheny Passage was selected in 2001 by the ATA after six years and more than 100 proposals as a name evocative of the geography and historical heritage of the trail. It was suggested by Bill Metzger, editor of the ATA newsletter. The runner-up was Allegheny Frontier Trail.[6]
Dravo Cemetery, originally the Seneca tribe's village known as Cyrie, later the home of the Dravo Methodist Church and Cemetery. Now a popular camping area and rest spot near Buena Vista, Pennsylvania.
Fallingwater, a national architectural landmark designed by Frank Lloyd Wright. Located very close to the trail, but not accessible from it.
Pinkerton Trestles and Tunnel, a trestle, 849 feet (259 m) long tunnel (unlighted; reopened in 2015) and trestle between the Markleton and Fort Hill trailheads[10]
Bollman Truss Bridge in Meyersdale, one of the two surviving cast-iron truss bridges in North America
the Eastern Continental Divide, the highest point of the trail, passes through a short tunnel with murals of the area's history and a map of the trail's elevation contours.
Big Savage Tunnel, 3,295 feet (0.6 mi; 1.0 km), the lit tunnel, carries the trail through Big Savage Mountain two miles east of the Eastern Continental Divide with a scenic vista just east of the tunnel—closed December 1 to April 1 for protection from seasonal snow and ice. Approximate dates, based on seasonal conditions. No easy road bypass.
Mason–Dixon line: where the trail crosses the Pennsylvania - Maryland state border
Cumberland Bone Cave: (two or three miles west of Cumberland, Maryland: an archeological site containing bones of saber-toothed cats and other extinct animals, discovered during construction of the railroad.