Colorado Street Bridge
Why it's listed
Colorado Street Bridge carries Colorado Boulevard across the Arroyo Seco in Pasadena. Built between July 1912 and December 1913, it is a reinforced concrete open spandrel arch structure with nine large parabolic arches, a total length of 1,467.5 feet and a maximum height of about 148 feet. Waddell and Herrington designed it, but the contractor altered the alignment, curving it to reach firmer foundations at lower cost. Pasadena voters approved a bond issue, and the Los Angeles City Council contributed funds because the west end reached its territory. At completion it was billed as the highest concrete bridge in the world. Residents later campaigned to save it from demolition in 1931 and to study its preservation after a 1977 state report found severe deterioration. It remains in use, though aging, and has been named a city cultural heritage landmark and a civil engineering landmark.
Significance in brief: The nomination presents it as a technically and visually impressive engineering work, proclaimed the highest concrete bridge in the world when it opened in December 1913. It is described as a transitional design combining modern scale with period finish and detail. It also contributed to Pasadena's growth by linking the city to Los Angeles and became an object of civic pride.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 81000156, listed February 12, 1981. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | Colorado Blvd., Pasadena |
|---|---|
| County | Los Angeles County |
| Listed | February 12, 1981 |
| Reference number | 81000156 |
| Resource type | Structure |
| Period of significance | 1912-13 |
| Architect / builder | Waddell and Herrington, engineers (contractor John Drake Mercereau named in the text) |
| Areas of significance | Commerce, Engineering, Transportation, Architecture |
| Level of significance | State |
| Status (as stated in the nomination) | Currently in use as a two-lane bridge, with deterioration (spalling, failed expansion joints and bearings, some rusting of steel) identified in 1976-78 state studies; the balusters of the railing have been lost. |
| Acreage | 1 |
| Within district | Pasadena Arroyo Parks and Recreation District |
| Coordinates | 34.14465, -118.16463 (NPS GIS) |
What listing means for this property
For a publicly owned building or structure, listing mainly matters when federal funds, permits or licences are involved: projects then go through Section 106 review so effects on the property are considered. Listing also strengthens applications for preservation grants and, for leased income-producing uses, can enable the federal rehabilitation tax credit.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 81000156.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5148962
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.