The Marin County Open Space District (MCOSD) is the local government agency responsible for preserving public open space in Marin County, California. Our mission is to enhance the quality of life in Marin through the acquisition, protection, and responsible stewardship of ridgelands, baylands and environmentally sensitive lands targeted for preservation in the Marin Countywide Plan. MCOSD lands represent outstanding examples of northern California environments including oak-bay woodlands, savanna, grasslands and salt marsh. These habitats are managed to protect and enhance their natural, undeveloped character while accommodating educational activities and trail-oriented uses such as hiking, horseback riding and mountain bicycling. Lands of the Open Space District, together with Marin’s extensive federal and state parklands, contribute to Marin County’s reputation as a highly desirable place to live and work.

District Information:
District Policies
District Code - Rules and Regulations
District Permits
Minutes & Agendas for the decommissioned Open Space and Trails Committee
MCOSD Annual Reports
MCOSD Core Programs
Marin County Parks
Public Transit to Outdoors
List serve – people who “subscribe”
Contact us / Staff list