As the name implies, the Conejo Open Space Conservation Agency (COSCA) has been entrusted with the responsibility of preserving, protecting and managing open space resources in the Conejo Valley. The Conejo Valley is generally described by the City of Thousand Oaks Planning Area.

COSCA was created in 1977 by a joint powers agreement between the City of Thousand Oaks ( and the Conejo Recreation and Park District (, enabling the two agencies to "jointly exercise their legal powers to create a jurisdictional framework for the conservation of natural open space lands, assure coordination of local land use and resource management decisions and establish an entity to focus community resources toward achievement of adopted General Plan goals." In this context, "open space" is defined as land which is in essentially a natural, undeveloped state, and does not include golf courses, developed park sites or landscaped greenbelts.

COSCA currently owns or manages 15,194 acres of open space and maintains more than 150 miles of trails. COSCA's staff includes two full-time administrative staff and six Rangers.


For the rules and regulations that apply to COSCA open space, please see COSCA Ordinance No. 01-2009.


COSCA's 2011-2012 Annual Financial Report

COSCA's 2012-2013 Annual Financial Report

COSCA's 2013-2014 Annual Financial Report


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By providing a refuge from urbanization for both people and wildlife, COSCA's open space system is an investment in the future. Unlike so many things in today's world, this is a resource which appreciates in value for both people and wildlife as the years go by. Hopefully, with your help, our open space system will continue to offer a safe, stable environment for all organisms, whose complex interactions combine to form viable ecosystems.

For more information about COSCA, contact COSCA Manager Shelly Mason at or (805) 449-2339.

COSCA Administrative Offices
City Hall/Civic Arts Plaza
2100 Thousand Oaks Boulevard
Thousand Oaks, CA 91362
(805) 449-2339
COSCA Ranger Headquarters
403 W. Hillcrest Drive
Thousand Oaks, CA 91360
(805) 381-2741