Before revision: North America United States Pennsylvania The four track route built by the Pennsylvania Railroad (PRR), the Horseshoe Curve that starts its climb along Kittanning Run due west of Altoona, and crosses two runs and three mountain faces using three gaps of the Allegheny.
After revision: North America United States Pennsylvania The four-track route built by the Pennsylvania Railroad (PRR), the Horseshoe Curve that starts its climb along Kittanning Run due west of Altoona, and crosses two runs and three mountain faces using three gaps of the Allegheny.