Pennsylvania Route 120 follows an old Native American Trail, the Sinnemahoning Path. This trail was used by Native Americans to cross the eastern continental divide (specifically the Allegheny Front) between the Susquehanna River (which drains into the Chesapeake Bay) and the Allegheny River (which forms the Ohio River with the Monongahela River at Pittsburgh and eventually drains into the Gulf of Mexico via the Mississippi River). American Pioneers also used the trail to make their way west and it was also known as the Bucktail Trail. As the technology of road building advanced, what was once a Native American Trail became the two lane highway known today as Pennsylvania Route 120.