The Allegheny Portage Railroad was the first railroad constructed through the Allegheny Mountains in central Pennsylvania. It operated from 1834 to 1854 as the first transportation infrastructure through the gaps of the Allegheny that connected the midwest to the eastern seaboard across the barrier range of the Allegheny Front. Approximately 36 miles long overall, both ends connected to the Pennsylvania Canal, and the system was primarily used as a portage railway, hauling river boats and barges over the divide between the Ohio and the Susquehanna Rivers. Today, the remains of the railroad are preserved within the Allegheny Portage Railroad National Historic Site operated by the National Park Service.
The railroad was authorized as part of the Main Line of Public Works legislation in 1824. It had five inclines on either side of the drainage divide running athwart the ridge line from Blair Gap through along the kinked saddle at the summit into Cresson, Pennsylvania.
Wikipedia https://en.wikipedia.org/wiki/Allegheny_Portage_Railroad
Official Website https://www.nps.gov/alpo/index.htm
Coordinates 40°25'47.137" N -78°34'27.696" E