Here in Skagit County, Washington state, the terrain is mountainous. A century ago they built temporary railroads into the woods to get timber out. Large trestles often were built since trains couldn't handle much of a grade. After the timber was cut, the whole camp would be removed on rails and the tracks taken up.
This train, however, is carrying limestone for the mills in town that made concrete. This rail line was short lived as they built a system of six cubic yard buckets that traveled overhead continuously. It was a dirty town at that time.
From the Concrete Heritage Museum, Concrete, Washington