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 3001 - Bridges
- 87 more...
- ItemWWASPSL7-027 - Spokane, Portland, and Seattle (SP&S) Trestle, Washington State, undated
- ItemWWASPSL7-044 - Spokane, Portland, and Seattle (SP&S) High Trestle, Washington State, undated
- ItemWWASPSL7-094 - Spokane, Portland, and Seattle (SP&S) Trestle at Spokane, Washington, circa 1907
- ItemWWASPSL7-120 - Spokane, Portland, and Seattle (SP&S) Tracks, Washington State, undated
- ItemWWASPSL8-041 - Spokane, Portland, and Seattle (SP&S) Trestle at Milepost 52, Oregon, undated
- ItemWWASPSL8-042 - Spokane, Portland, and Seattle (SP&S) Trestle at Milepost 52, Oregon, undated
- ItemWWASPSL8-043 - Spokane, Portland, and Seattle (SP&S) Trestle at Milepost 52, Oregon, undated
- ItemWWASPSL8-044 - Spokane, Portland, and Seattle (SP&S) Trestle at Milepost 52, Oregon, undated
- ItemWWASPSL8-057 - Spokane, Portland, and Seattle (SP&S) Bridge at Clatskanie, Oregon, undated
- 12 more...