"...Even if it's as Big as a Mountain!" The first railroad to circumvent the Allegheny Mountains, the Allegheny Portage Railroad was the finishing piece of the Pennsylvania Mainline Canal. "The Portage," opened in 1834, marking the first time that there was one, direct route between Philadelphia and Pittsburgh. All things to all people, it served merchants, passengers, slaves in pursuit of freedom, and soldiers from the Mexican War. The park grounds are open from sunrise to sunset.