Mower Lumber Company No. 4 Is a Shay - 3 truck it was built in 1922 by the Lima Locomotive Works for the Birch Valley Lumber Company at Tioga, WV, as #5.
It was use as a logging engine for the Birch Valley Lumber Company until 1943 when it was sold to the Mower Lumber Company and renumbered #4 However, with the impending purchase of the railroad by the State of West Virginia, #4 was spared the torch and used to provide free demonstration runs between Cass depot and the shop during September and October 1961. One year later it was finally sold to the State of West Virginia in 1962.
Today the engine is operational at the Cass Scenic Railroad.