Railroad Archives Online
- CollectionD0063 - Walter W. Ainsworth Collection
- Series007 - Spokane, Portland, and Seattle Railway
- Subseries Level 1014 - Photographs
- Subseries Level 2003 - Railroads--Buildings and Structures
- Subseries Level 3003 - Maintenance Facilities
- ItemWWASPSL1-042 - Spokane, Portland, and Seattle (SP&S) Turntable and Roundhouse, Portland, Oregon, undated
- ItemWWASPSL1-052 - Spokane, Portland, and Seattle (SP&S) Engine Terminal, Portland, Oregon, February 23, 1943
- ItemWWASPSL1-053 - Spokane, Portland, and Seattle (SP&S) Hoyt Street Roundhouse, Portland, Oregon, 1944
- ItemWWASPSL1-054 - Spokane, Portland, and Seattle (SP&S) Hoyt Street Roundhouse Turntable, Portland, Oregon, undated
- ItemWWASPSL1-056 - Spokane, Portland, and Seattle (SP&S) Hoyt Street Roundhouse, Portland, Oregon, undated
- 9 more...