Mount Lassen Drive Bridge Rehabilitation



Mount Lassen Drive is a divided roadway, crossing over Miller Creek on two separate bridge structures. The proposed Project will repair components of the existing northbound bridge over Miller Creek. The installation of a curtain wall and concrete closure wall will repair the embankment erosion and exposed steel pile at the north abutment of the northbound bridge. No work will occur on the southbound bridge structure. The project will also install bank and channel stabilization measures beneath and downstream of the northbound bridge The bridge repairs will require temporary creek diversion through the Project site. Construction activities are expected to be completed in one season between June 15 and October 15.

As is standard with all Marin County Public Works projects, the contractor will be required to control any runoff or erosion from the project site into any/all nearby waterways and conduct a full site cleanup once project is complete.


The estimate for the project is $400,000 dollars. The project is federally funded by a grant from the Highway Bridge Program (HPB).  The purpose of the HPB is to replace or rehabilitate public highway bridges over waterways or other topographical barriers including highways or railroads.

Traffic Impacts

Given the width of the northbound roadway, the lane of travel on the northbound bridge is expected to remain open to traffic during construction. However, the construction contractor may have to close the northbound bridge during construction for short term daytime closures. The northbound vehicles will be routed to the southbound bridge with stop control.



  • Q2/Q3 2024 – Secure NEPA clearance
  • Q3/Q4 2024 – Start environmental permitting, utility coordination, and temporary construction easements
  • Construction TBD
Close window