Lost Mare Island Causeway SOC Bridges over Napa River in Vallejo, CA

1919: 2-lane wood SOC bridge

1935: 3-lane concrete SOC bridge, this was a WPA project

1980: (Bridge Hunter; 3D Satellite) this increased the navigation channel width from 75' to 100'.

The causeway is now named "Ernest D Wichels Causeway," who was the only person to see all three bridges dedicated.

I wonder how much work the navy still does here.

SOC = Strauss Overhead Counterweight

Mare Island Museum posted
[An extensive history, it is well worth a mouse click or screen tap.]
Douglas Butler shared
Credit to Mare Island Museum: The Mare Island Causeway Shipyard Bascule Bridge is a Strauss Overhead Counterweight Trunnion Bascule Bridge designed by the Strauss Bascule Bridge Co. and built in 1935 by the Barett Hilp. This bridge crosses the Mare Island Strait in Mare Island and Vallejo, CA. Used by Road and Railroad Interurban, Sacramento Northern Railway, San Francisco & Napa Valley Railroad, Napa & Calistoga Railway, and US Military Transportation, the bridge was the second bridge built and was replaced with a vertical lift bridge in 1980.

Mare Island Museum also posted
Mare Island Causeway Bridges #1 and #2
[Note that the first bridge also used a SOC design.]

John McCory, Aug 2022

Street View, Aug 2022

Parker Pringle posted
The Cal Northern's Napa Junction yard job is headed across the Mare Island Causeway after delivering a Caltrain locomotive to Alstom for a mid-life rebuild. June 2020.

FJ Caron: Is there no vehicular traffic allowed on the bridge?

Nick Perata: FJ Caron they hold traffic while train crosses if I remember correctly

April 2025:

Sean Bates posted

I was passing through the Bay Area on my way home and saw the Mare Island Causeway Bridge open and decided to swing by for a closer look. 

The barge had already passed by the time I got there, so it was closing again, but I always thought this little mixed-traffic bridge was fun given it's simple design and integrated street-run heavy rail line. 

Most of the rails on Mare Island have been abandoned for many decades, but Alstom had a caltrans railcar shop active just on the other side of the bridge, which apparently closed up business early this year. 

I believe that means this spur is once again abandoned, though it's possible a new customer will take over the Alstom facility and utilize the rails.

Mike G Content: There are no more customers on this line, a housing firm has been attempting to push out all business from the island and fill it with luxury homes.

Cliff Orriss: Mike G Content I doubt they will be successful because the island is heavily contaminated from years of ship and submarine building. Plus NOAA still uses the facilities there for their vessels. My dad was stationed there in the 70's. Sad to see it now 🙁

Owen David commented on Sean's post
The last train back in December [2024]