At 4.5 miles, from end to end, the Waterville Railroad, reporting marks WRR, was easily the shortest common carrier in the US.
Waterville, Washington is the County Seat of Douglas County, and is easily the highest incorporated town in the state, at 2,625 feet above sea level. ITs also the center of a large wheat producing region, the Waterville Plateau, part of the great Columbia Basin. The Great Northern Ry Co, wanting to capitalize on this, decided to run a line up Moses Coulee. following Douglas Creek. Waterville, being the County Seat, expected the GN to build the branch to them, but the GN was more interested in the economics of the deal, and built the branch to Mansfield, instead. Not to be deterred, Waterville raised $80,000 and built their own, 4.5 mile railroad, from the town center, to the junction at Douglas.
The Story of the Waterville Railway
GN 1147 at Mansfield Depot, Winter, 1947. 1147 is on static display, stuffed and mounted in Railroad Park in Wenatchee, WA, near Appleyard, having been donated by the GN in 1956. I was lucky enough to have gotten a cab ride as a 9 year old, before she was taken out of service.