Richardson Bay Bridge Milestones

The Redwood Bridge circa 1932  |  Photo from Anne T. Kent California Room, Marin County Free Library  |  post by Larry Clinton

The recent announcement of late-night lane closures for emergency repairs to finger joints on the Richardson Bay Bridge aroused my curiosity about the history of the local landmark, which is a prominent feature of our view from Gate 6 ½ in Kappas Marina.

In the Anne T. Kent California Room’s Community Newsletter, historian Robert Harrison tells the story of the bridge’s evolution:

The Richardson Bay California Redwood Bridge, spanning 2,452 feet, was completed in 1931. This bridge was an important link in the new State Highway 101 going from San Rafael to Sausalito. The bridge provided a four-lane roadway from Manzanita, just north of Sausalito, to De Silva Island in Strawberry. It included a 56-foot lift section to allow the passage of marine traffic.

The bridge, known as the Redwood Bridge, was constructed of more than two million board feet of redwood timber including over 600 redwood piles making it the largest redwood structure in the world. The bridge engineers reported that redwood was selected because it was “most suitable for a permanent structure of the character required, not being subject to dry rot or the destructive effects of close proximity to salt water.”

The Richardson Bay Freeway Bridge, spanning 2,864 feet was completed in 1956, replacing the Redwood Bridge with a six-lane concrete and steel bridge. It was 86 feet wide and had a 35-foot clearance above high water. The replacement bridge was constructed parallel to and just east of the Redwood Bridge at a cost of $3.2 million (about $28 million today).

It’s the bridge that carries traffic over the north arm of Richardson Bay today. Though this new bridge lacks the character of the Redwood Bridge, it remains the only long bridge spanning a body of water entirely within the boundaries of Marin County.

Environmental concerns, the diminished role of the railroad, and better roads were all factors which eliminated Marin’s need for long bridges to travel short distances. Yet a glance at the history of these projects reminds one of the creativity and bold concepts of early transportation entrepreneurs.

Following the 1989 Loma Prieta earthquake the concrete bridge was seismically upgraded and widened to 138 feet to accommodate nine lanes of traffic.

According to a report in a January 1995 issue of this newspaper, that seismic upgrade became a political flashpoint in the mid-90s, when the Bay Conservation and Development Commission (BCDC) refused to approve the project on the grounds that Caltrans’ plan to fill in the base of the bridge with concrete walls would block a view corridor.

Caltrans lobbied Republican governor Pete Wilson to intervene, and Wilson teamed with State Senator Milton Marks in attempt to eliminate the BCDC by defunding the commission and turning its caseload over to the California Coastal Commission.

That led to an unusual coalition between environmentalists and developers, who opposed the governor’s plan on the grounds that “the enemy we know is better than the enemy we don’t know.”

At the time, the Coastal Commission was dominated by Southern California commissioners and staffers and had at least as contentious a reputation as the BCDC. It was feared that turning over existing cases to regulators unfamiliar with them would just grind everything to a halt. So, stakeholders from usually opposing camps came together and helped to keep the BCDC as the regulator of San Francisco Bay. As past president of the Floating Homes Association, I was part of that coalition, and recall one dinner meeting when I was seated next to Sylvia McLaughlin, cofounder of the Save San Francisco Bay Association, a pioneering environmental organization featured in the film “Rebels with a Cause.” She was a charming dinner companion and a determined crusader.

Caltrans has announced that the repair work will keep the on-ramps from Bridgeway and Shoreline Highway in Mill Valley closed from 10:00 p.m. until 6:00 a.m. up to June 18. During those hours, traffic is being detoured via southbound 101 to the Spencer Avenue exit, then to Monte Mar Drive and northbound 101. A Caltrans spokesperson says the closures are necessary to ensure the safety of construction workers replacing expansion joints.