By 1916, Sierra Railway No. 18 had been rebuilt with new Superheater units and piston valves as an experiment by the railroad to consider the efficiency of these fittings for future locomotive acquisitions.
No. 18 was retired from service in 1952 when its tube time expired.
During the locomotive's annual inspection in 1952, excessive wear was found on No. 18's sidesheets. This issue deemed the locomotive unfit for continued service.
The locomotive sat on a siding at Jamestown until 1966 when it was sold to a private owner and moved to a trailer sales lot near Lodi, California.
Eventually, Fred Kepner purchased and moved this locomotive along with former Sierra Railroad No. 36 to their current location in Merril, Oregon.
- This locomotive was the railroad's first consolidation and was the most powerful rod-type locomotive on the roster at the time.
- When locomotive was sold to Fred Kepner it currently sits derelict in a field near Merrill, Oregon.
- Like Sierra Railway No. 3, this locomotive appeared in several films, such as ""The Cimarron Kid", "The Bad Men in Missouri", "The Texas Ranger", "Dodge City", "Wyoming Mail", " Go West", "Duel in the Sun", "Take Me Out to the Ball Game", "My Little Chickadee", "Last Train From Gun Hill", “The Return of Frank James”, and the opening of "The Harvey Girls"
- In a couple of movies it poses as ATSF #18.