The Great Allegheny Passage (GAP) is a 150-mile non-motorized trail that extends from the forks of the Ohio River at Pittsburgh to Cumberland County, MD, where it joins with the C & O Canal Towpath, and links to Washington, D.C., for a combined total of 334.5 miles. There is also a 52-mile spur connecting downtown Pittsburgh with the Pittsburgh International Airport. The GAP provides opportunities for hikers, bicyclists, cross country skiers and people with disabilities to discover the region’s beauty in river gorges, mountain vistas and sweeping cityscapes and experience waterways, wildlife, plants and rock formations. Rehabilitated massive railroad bridges and tunnels let trail users pass through the Allegheny Mountains, not over them. There are numerous trailheads that offer parking, water and toilets, as well as four Visitor Centers that provide amenities and information. Additionally, more than 30 interpretive signs have been installed to date. Over 750,000 people, from all over the globe, visit the GAP annually with estimated spending of over $12 million/year in the trailside communities. The Allegheny Trail Alliance, working in partnership with the two states, five counties, multiple municipalities, and other stakeholders, was responsible for bringing the GAP to fruition and continue to be engaged in its stewardship.