Railroad Archives Online
- CollectionD0197 - Maple Valley Historical Society Collection
- Series004 - Pacific Coast Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3006 - Cabooses (Railroads)
- ItemP11.14.9 - Pacific Coast Railroad caboose number 52 near Maple Valley, Washington in 1951.
- ItemP11.14.39 - Pacific Coast Railroad caboose number 53 at Seattle, Washington in 1949.
- ItemP11.14.63 - Pacific Coast Railroad caboose number 55 at Seattle, Washington, circa 1946.
- ItemP11.14.64 - Pacific Coast Railroad caboose number 52 at Renton, Washington, circa 1946.
- ItemP11.14.68 - Pacific Coast Railroad caboose number 55 at Seattle, Washington in 1951.