County Landmark 188
Monte Rio Bridge
Bohemian Highway over Russian River
Monte Rio
Built 1934

Monte Rio Bridge is an uncommon example of a multi-span pony truss with five spans. Truss bridges usually have metal railings, but this bridge has cantilevered sidewalks with concrete balustrades. The length of the bridge, the pony trusses, and the balustrades make this bridge more streamlined than most truss bridges.

The opening of the bridge was met with a surprising amount of fanfare for a bridge of its size, with ribbon-cutting ceremonies attended by a number of dignitaries including the governor.

Source: historicbridges.org

In 2012, Caltrans found problems with the bridge including seismic vulnerability, crumbling foundations and poor access for cyclists and walkers. Initially, Caltrans calculated that building a new bridge would be cheaper than repairing the old one.

When the projected costs rose from $25 million to $88 million, Sonoma County and Caltrans decided to upgrade the existing bridge rather that replace it even though a new bridge would probably last 75 years while the retrofitted bridge may only last 15 years.

Source: The Press Democrat, 7 August 2023