- Allegheny Portage Railroad National Historic Site Located in Gallitzin, PA TRAVEL BASICS - CAMPING - LODGING ACTIVITIES - FACILITIES - FEES/PERMITS Allegheny Portage Railroad NHS - The Lemon House (NPS Photo) IN BRIEF The Allegheny Portage Railroad was the first railroad constructed over the Allegheny Mountains. This inclined plane railroad operated between 1834-1854 and was considered a ...www.nps.gov/alpo