Colorado Street Bridge at 100: The Birth of a Pasadena Landmark

The Colorado Street Bride: Pasadena's answer to the Rome's aqueducts. Colorized, ca. 1915 photo courtesy of the Pasadena Public Library.

Pasadena's Colorado Street Bridge, which turns 100 this December 13, bears more than a passing resemblance to an ancient Roman aqueduct. In a way, that makes sense. Both use the same engineering solution -- colossal arches -- to create an artificial topography and overcome the natural contours of the land.

In Pasadena's case, those contours are the consequence of the Arroyo Seco, a seasonal watercourse that flows through a deep ravine from the base of the San Gabriel Mountains to its confluence with the Los Angeles River. Pasadena's historic core sits atop an elevated mesa that, to the west, drops suddenly into the arroyo. To get from Pasadena to Highland Park, Garvanza, and other westward settlements, travelers faced two obstacles: the stream of the Arroyo Seco itself, and its ravine.

The earliest bridge in the area -- J.W. Scoville's wooden trestle span, built in the late 1880s -- overcame only the first obstacle. Travelers still had to descend into the ravine, cross the bridge, and then climb the opposite bank -- a true hardship for horse-drawn vehicles, but an almost insurmountable one for the early automobiles that began using the bridge around the turn of the 20th century. So when Pasadena resolved to build a new bridge that would extend Colorado Street over the Arroyo Seco, it commissioned a structure that would cross the ravine at street level.

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Based on a design by engineer Joseph Alexander Low Waddell with modifications by builder John Drake Mercereau, the Colorado Street Bridge spans 1,467½ feet with the aid of 11 arches. At its tallest, the reinforced-concrete structure soars nearly 150 feet above the streambed.

Upon its completion it was hailed as the longest and tallest bridge in Southern California. But what makes the structure's scale even more impressive are two charming quirks: a 52-degree curve in the bridge's center, and a constant 2.65 percent grade -- a result of the fact that the east bank is 30 feet higher than the west.

Construction began in July 1912 and lasted 18 months, employing 40 to 100 workers on any given day. Built with 11,000 cubic yards of concrete -- made from gravel collected from the arroyo -- and 600 tons of steel reinforcement, the bridge cost a total of $235,000.

In later years, the bridge carried the fabled Route 66 over the arroyo and transformed Colorado Street into Pasadena's main commercial corridor. To accommodate the increased auto traffic, the city widened Colorado by 28 feet between 1929 and 1930, slicing off the facades of old buildings. In 1958, it promoted Colorado Street to the status of boulevard.

But such change was still decades off when, on December 13, 1913, Pasadena residents climbed into their automobiles -- specially decorated for the occasion -- and paraded across the span, celebrating the creation of their city's most enduring visual landmark.

The Scoville Bridge, seen here in 1889, traversed the stream of the Arroyo Seco but still required travelers to descend into the ravine and then climb the opposite bank after crossing. Courtesy of the Pasadena Museum of History.

The Colorado Street Bridge under construction in 1913. Courtesy of the Harrington & Cortelyou, Inc. Consulting Engineers Collection, Pasadena Public Library.

The Colorado Street Bridge under construction in 1913. Courtesy of the Harrington & Cortelyou, Inc. Consulting Engineers Collection, Pasadena Public Library.

A view of the Scoville Bridge next to the partially completed Colorado Street Bridge. Courtesy of the Pasadena Museum of History.

An electric car crosses the Colorado Street Bridge in 1930. Courtesy of the Pasadena Museum of History.

Countless photographers and postcard makers have turned their cameras toward the Colorado Street Bridge. Courtesy of the Frasher Foto Postcard Collection, Pomona Public Library.

Dozens of people have leapt to their deaths from the bridge, known by some as 'Suicide Bridge.' Courtesy of the Herald-Examiner Collection, Los Angeles Public Library.

As plans for a new, wider highway bridge, shown here under construction in 1953, were being finalized, the fate of the Colorado Street Bridge was uncertain. Pasadena eventually elected to keep it. Courtesy of the USC Libraries - Los Angeles Examiner Collection.

A 1951 artist's rendering of a new freeway span next to the original Colorado Street Bridge. Courtesy of the Metro Transportation Library and Archive.

The Colorado Street Bridge was closed from 1989 to 1993 for a $27 million seismic retrofitting project. Courtesy of the Photo Collection - Los Angeles Public Library.

L.A. as Subject is an association of more than 230 libraries, museums, official archives, cultural institutions, and private collectors. Hosted by the USC Libraries, L.A. as Subject is dedicated to preserving and telling the sometimes-hidden stories and histories of the Los Angeles region.

About the Author

A writer specializing in Los Angeles history, Nathan Masters serves as manager of academic events and programming communications for the USC Libraries, the host institution for L.A. as Subject.
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