Primary Sources
Images:
- Map of important Indian Paths in Pennsylvania, circa 1770.
- A view of Pine Creek Gorge (a.k.a. Pennsylvania Grand Canyon) in autumn.
- Canal boat being pulled by mules, Lehigh Canal, circa 1900.
- Observation End of the Pennsylvania Limited, by William Rau, circa 1895.
- A 1940s style automobile parked next to a road, outside a tunnel. Over the tunnel entrance is a sign that reads "Allegheny Mountain