NS 1800 pokes out of the Allegheny Tunnel on its way west.
This tunnel is actually the oldest of the three bores through the summit of the Allegheny Escarpment at Gallitzin. Originally called Summit Tunnel, Allegheny Tunnel was opened to traffic in 1854.
The New Portage Tunnel, on the other side of town, was built by the Commonwealth to replace the original Portage Railroad of the Canal System and opened the following year.
The youngest bore, the one that is properly named the Gallitzin Tunnel, opened in 1904. It was the only bore not enlarged by Conrail to accommodate double-stack container trains in the mid-1990s, and was closed and later sealed up.