Railroad Archives Online
- CollectionD0063 - Walter W. Ainsworth Collection
- Series007 - Spokane, Portland, and Seattle Railway
- Subseries Level 1014 - Photographs
- Subseries Level 2004 - Railroad tracks
- Subseries Level 3001 - Railroad mainline
- 32 more...
- ItemWWASPSL2-052 - Spokane, Portland, and Seattle (SP&S) Tracks at the Locks, Cascade Locks, Oregon, undated
- ItemWWASPSL4-009 - Spokane, Portland, and Seattle (SP&S) Track and River View at Cooks, Washington, undated
- ItemWWASPSL4-018 - Spokane, Portland, and Seattle (SP&S) SP&S Track and Columbia River at Underwood, Washington,1912
- ItemWWASPSL4-019 - Spokane, Portland, and Seattle (SP&S) SP&S Track and Columbia River at Underwood, Washington, 1912
- ItemWWASPSL4-093 - Spokane, Portland, and Seattle (SP&S) Mainline, Washington State, undated