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 ridge and bay lands 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. The Marin Open Space Program offers seasonal trips and events for both families and individuals. Download Ranger Led Events for outdoor ideas.

Marin County won a Savvy Award for a Peter Coyote-narrated video that celebrated the 40th anniversary of Marin County Parks. Watch it here: