<P> The District provides regional bus and ferry transit service throughout the Golden Gate Corridor, which runs from San Francisco to Sonoma County . The District does not operate transit service in Napa, Mendocino, or Del Norte counties . Within Marin County, Golden Gate Transit is the contractor for a majority of bus service provided by Marin Transit, a relationship that dates to 1971 . Golden Gate Transit has operated bus service across the Richmond - San Rafael Bridge to Contra Costa County on behalf of the Metropolitan Transportation Commission since 1993 . </P> <P> The District's primary revenue source is tolling on the southbound lanes of the Golden Gate Bridge . A mix of tolls, transportation subsidies, and grants is used to support bus and ferry services . </P> <P> The District has a 19 - member board of directors: </P> <Ul> <Li> Nine Directors represent San Francisco <Ul> <Li> One is appointed by the Mayor </Li> <Li> Four are elected members of the Board of Supervisors </Li> <Li> Four are non-elected people appointed by the Board of Supervisors </Li> </Ul> </Li> <Li> Four Directors represent Marin County <Ul> <Li> Two are elected members of the Board of Supervisors </Li> <Li> One is an elected member of the Council of Mayors and Councilmembers and is appointed by the Board of Supervisors </Li> <Li> One is a non-elected person appointed by the Board of Supervisors </Li> </Ul> </Li> <Li> Three Directors represent Sonoma County <Ul> <Li> One is an elected member of the Board of Supervisors </Li> <Li> One is an elected member of the Council of Mayors and Councilmembers and is appointed by the Board of Supervisors </Li> <Li> One is a non-elected person appointed by the Board of Supervisors </Li> </Ul> </Li> <Li> One Director each represent Napa, Mendocino, and Del Norte counties <Ul> <Li> Each is a non-elected person appointed by the respective Boards of Supervisors </Li> </Ul> </Li> </Ul>

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