The Tuscarora Mountain Tunnel is one of four original Pennsylvania Turnpike tunnels still in active use. A second tube was bored in the late 1960s to ease traffic conditions. The tunnel measures in length and is the second-longest active tunnel on the turnpike. The Sideling Hill Tunnel is the longest overall, but was abandoned in 1968. The Allegheny Mountain Tunnel is the longest in active use. The Tuscarora Mountain Tunnel sits on the Huntingdon/Franklin County line.