Marin County Parks and Open Space Department

The Marin County Open Space District (MCOSD) manages 250 miles of roads and trails on 34 open space preserves. Roads and trails may be temporarily closed, or use restricted, due to safety, wet weather, natural hazards, wildland fire, construction, or restoration. Please cooperate with closure signs and notices, and take alternate routes.

Project Impacts and Closures

Loma Alta Preserve

Sections of Old Railroad Grade and Fox Hollow Trail in Loma Alta Preserve will be temporarily closed from mid-September to mid-October 2018 for trail improvement work. Four small ephemeral stream crossings will be upgraded. Funded by Measure A, the restoration and access improvements will reduce sediment from entering the watershed and help maintain safe and sustainable trails. Work is scheduled to begin September 17, 2018.

Baltimore Canyon Preserve

Last winter two landslides occurred in this preserve and impacted the Southern Marin Line Fire Road. Starting August 6, 2018 and ending October 1, 2018, the Marin Municipal Water District (MMWD) will repair the first of the two slides. During this time, the Southern Marin Line Fire Road is closed to all public access, Monday through Friday, from 7am to 5pm. Access may be allowed after 5pm during the week, and during the day on weekends. Please respect closure signs and project notices. For more information, read the MMWD news release. Repairs on the second slide are scheduled to begin October 1, 2018 and end December 30, 2018.

Seasonal Closures


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We update this page when closures, openings, or conditions change.