At the Hills station, the PRR was north/west of the Chartiers creek, while the Montour Railroad was on the other side of the creek. Just north of the Hills station, there was an interchange between the PRR and the Montour. The Montour provided a lot of two-bay hoppers loaded with coal that the PRR took to Pittsburgh.
Just south of the Hills Station, the PRR track crosses the Chartiers creek to join the Montour Railroad's track on the other side. The Montour track was built later in 1913/14, and sits at a higher elevation than the PRR's track.
Today, the former Montour RR track is called the Montour Trail. The Montour Trail was completed in 2008.
In 1946 the Pennsylvania Railroad and the Pittsburgh & Lake Erie railroad (a subsidiary of the New York Central RR) became co-owners of the coal-hauler the Montour Railroad. The Montour RR also interchanged traffic at McDonald with the PRR. The Montour RR had about 40 miles of track that roughly circled the west side of Pittsburgh, PA. It used 2-8-0 and 2-8-2 steam engines, which were later replaced by the 1200hp SW9 EMD diesel engines. The book Mid-Sized and Manageable Track Plans by Iain Rice describes how to build a 12'x12' HO-scale layout based on the Montour, which includes several prototype photos.