Mountain View Road Bridge Replacement Project

Rosemarie Gaglione, Director, Public Works

Project Description:

The County of Marin has received federal funding to replace local bridges that have been identified as structurally deficient and functionally obsolete. Mountain View Road Bridge over San Geronimo Creek is one of the bridges identified for replacement and a project has recently been initiated to conduct environmental studies and to begin design work.

Protecting the riparian habitat, avoiding creek impacts and integrating stream bank restoration into the project will be a high priority.

Mountain View Road Bridge is located just south of Sir Francis Drake Boulevard in the community of Lagunitas. Mountain View Road is a narrow paved roadway that provides access to residential properties on the south side of San Geronimo Creek.

The existing bridge was built in 1962 and is a three-span, steel railroad car frame structure with timber deck runners and wooden bridge railings. The bridge needs to be replaced for the following reasons:

  • The existing steel supports are rusting and have experienced minor structural section loss
  • Erosion along the north bank has caused the rock slope protection to be undermined
  • The existing narrow bridge deck provides for only one lane of traffic
  • Bridge railings do not meet current safety standards

The project improvements are anticipated to extend from the intersection at Sir Francis Drake Boulevard to conform points on the south side of the creek along Mountain View Road and Corona Avenue. During construction, the Mountain View Road Bridge may need to be temporarily closed. If this were to occur, traffic would be detoured to the Lagunitas Road Bridge.

The project is 100% federally funded through the Highway Bridge Program and Toll Credits. The federal funds are being administered through the Caltrans Local Assistance Program.

The anticipated project timeline is as follows:

Summer 2015
Begin Environmental Studies and Preliminary Engineering
Spring 2016
Community Workshop – Informational Presentation
Summer/Fall 2016 
Preliminary Engineering, Prepare Updated Design Documents
Spring 2017 Community Workshop – Presentation and Discussion of Updated Design
Spring 2019
Initiate Detailed Design
Summer 2020
Conclude Environmental Review
Spring 2021 Final Design Plans
Summer 2021 Begin Construction


Community outreach and engagement are fundamental to developing the design of the new bridge. The project development process will integrate the community’s vision and resident needs so that they are reflected in the final design.

Upcoming Community Meeting:

April 26, 2017, at 6p.m., located on-site at the Mountain View Road Bridge in San Geronimo. View the public notice here.

Materials from the March 17, 2016, community meeting can be accessed with the links below:

Presentation Materials

Summary Report

Stay Informed:

For more information, contact Chris Good, Associate Civil Engineer.