Most of the branch lines in the Palouse were built with a "path of least resistance" philosophy: If an obstacle was encountered, find a way go around it or over it. This becomes abundantly clear when one wanders along these lines, both existing and abandoned, as they closely follow waterways, take advantage of naturally-formed canyons and snake amongst the region's characteristic rolling hills.
However, sometimes the engineers came to a barrier that left them no choice but to move a significant amount of dirt and rock so they could create an efficient passage to the other side. Such is the case on the south approach to St. John, where the Palouse River & Coulee City Railroad's PV Sub reaches the head of Downing Creek's valley and punches through a ridge line to reach its namesake Pleasant Valley. With a dead-in-tow GP40 (shut down to conserve fuel) and 15 empties on the draw bar, a distinctly ex-C&NW GP50 passes freshly-cut wheat stalks as it works hard to reach the summit at Milepost 16.5.