The Allegheny Portage Railroad was the first railroad constructed through the Allegheny Mountains in central Pennsylvania, United States; 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 long overall, both ends connected to the Pennsylvania Canal, and the system was primarily used as a portage railway, haulting 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.