This line was initially constructed in stages between 1917 and 1929, mainly for the benefit of Weyerhaeuser Lumber Company. Changing market conditions for wood products led to this line's abandonment in 1990. Part of the route is now a trail.
The route includes two switchbacks to help navigate the mountains in the area. The mountain on which the switchbacks are located is appropriately named "Switchback Hill".
Thanks to Craig Bass for contributing information about this route.