Major Impacts to Cycling on Weekdays Road & Trail Closures Near Fairfax

Construction Impacts Cycling in Fairfax, Mt. Tam Watershed

There will be major impacts to cycling on weekdays near Fairfax and on Mt. Tam Watershed. Two major construction projects underway in the Ross Valley will impact cycling along popular routes in Fairfax, Ross, and the Mt. Tam Watershed through November. Expect delays and closures on weekdays on Bolinas Road, Concrete Pipe, and Shaver Grade at Phoenix Lake.

Watershed Road and Trail Closures for Tank Construction Project

Marin Water will be closing some watershed fire roads and trails as construction work continues on the Pine Mountain Tanks Project. These closures are in addition to the closure of Concrete Pipe Road at Bolinas-Fairfax Road already in place from Mon – Fri from 8 a.m. to 5 p.m. The new closures to fire roads and trails begin Monday, August 21st through October 2023.

Starting August 21st, the District’s contractor will begin roadwork and truck hauling along Concrete Pipe, Shaver, and Phoenix fire roads. Starting September 5th, the Contractor expects to begin off-hauling soil from the watershed along this route. During this period, the District will be doing outreach to visitors and enforcing the closures. There will be traffic control points at Five Corners to accommodate visitors. There will also be a control point at the Natalie Coffin Greene Park parking area. Below is a map that delineates the access changes in place during this construction activity. Note the yellow circles with ‘X’s on the map identify the hard closure points where through-access will not be permitted Mon – Fri from 8 a.m. – 5 p.m.

The closures will be in place to ensure the safety of both watershed visitors and construction workers. Please allow extra time when planning your visit to/from the watershed, use caution when traveling near areas of construction or heavy equipment, and please adhere to all closure signs and barricades. Thank you for your patience while this important water infrastructure project is underway.

For further information, please visit the project website at

Map of trail closures on Mt. Tam Watershed

Bolinas Road Slide Repair near Sky Oaks

The series of storms that hit Marin County in January 2023 damaged roads across the county. Bolinas Road, a primary route between Ross Valley and West Marin, is one of the storm-damaged roads. Access has been limited to just one lane at milepost 1.34 near Fairfax since January. During the storm, earth slid out from under Bolinas Road at approximately 850ft east of the Sky Oaks Road intersection. The damage posed an immediate public safety hazard, and the eastbound lane was closed. The slide area was secured, and traffic control measures have been in place to allow for alternating two-way traffic through the westbound lane.

The construction phase of the Bolinas Road repair project is underway and is expected to be finished in early November. Construction work hours are anticipated to be weekdays from 8 a.m. to 6 p.m. Weekend work may be permitted as necessary and would be announced in advance to minimize inconvenience to travelers.

Most of the construction phase work will be performed with the same single-lane closure setup that has been in place since the roadway was damaged. Traffic control measures will remain in place for the duration of the project, allowing alternating two-way traffic through the westbound lane. Drivers and cyclists are required by law to adhere to all roadway laws, which include following the construction signage and traffic control measures, such as the temporary traffic light that is already in place.

For further details visit

Slide area along Bolinas-Fairfax Road

If you have specific questions about the closures, you can also reach out to

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