Mare Island Mare Island is a peninsula in the United States alongside the city of Vallejo , California , about northeast of San Francisco . The Napa River forms its eastern side as it enters the Carquinez Strait juncture with the east side of San Pablo Bay . Mare Island is considered a peninsula because no full body of water separates this or several other named " islands " from the mainland . Instead , a series of small sloughs cause seasonal water - flows among the so - called islands . Mare Island is the largest of these at about long and a mile wide . The Napa River widens and forms a harbor between Mare Island and the mainland . History . In 1775 , Spanish explorer Perez Ayala was the first European to land on what would become Mare Island - he named it " Isla de la Plana " . This area was part of Rancho Suscol , deeded to General Mariano Guadalupe Vallejo in 1844 . It became a waypoint for early settlers . In 1835 , whilst traversing the Carquinez Strait , a crude ferry transporting men and livestock capsized in a squall . Among the livestock feared lost in the wreckage was the prized white mare of General Mariano Guadalupe Vallejo , the Mexican Commandante for Northern California . Several days later , General Vallejo ' s mare was found on the island , having swum ashore . Grateful for the fortunate turn of events , he renamed the island to " Isla de la Yegua " , Spanish for Mare Island , in her honor . Shipyard . In 1850 United States Navy Commodore John Drake Sloat led a survey party in quest of a logical site for the nation ' s first Pacific naval installation . Sloat recommended the island across the Napa River from the settlement of Vallejo , as it was " free from ocean gales and from floods and freshets . " On November 6 , 1850 , two months after California was admitted to statehood , President Fillmore reserved Mare Island for government use . The Navy Department acted favorably on Commodore Sloat ' s recommendations and Mare Island was purchased for use as a naval shipyard in July 1852 at a cost of $ 83 , 410 . On September 16 , 1854 , Mare Island became the first permanent US naval installation on the west coast , with Commodore David Farragut , as Mare Island ' s first commander . For over a century , Mare Island was the Navy ' s Mare Island Naval Shipyard . The growing size and number of the country ' s naval fleet was making older facilities obsolete and led to increased building and refitting of shipyards nationally . In 1872 the US Public Works Department commenced construction of a drydock on the island , setting it on a foundation of cut granite blocks . The work was completed in 1891 . A second drydock was begun in 1899 , a concrete structure long set on wooden piles ; it was completed in 1910 . By 1941 a third drydock had been completed and drydock number four was under construction . The ammunition depot and submarine repair base were modern , fireproof buildings . A million dollar , three - way vehicle causeway to Vallejo replaced a ferry service . Before World War II , Mare Island had been in a continual state of upbuilding . By 1941 , new projects included improvements to the central power plant , a new pattern storage building , a large foundry , machine shop , magazine building , paint shop , new administration building , and a huge storehouse . The yard was expected to be able to repair and paint six to eight large naval vessels at a time . Several finger piers had recently been built , as well as a new shipbuilding wharf , adding one and a berth . It employed 5593 workers at the beginning of 1939 , and rapidly increased to 18 , 500 by May 1941 , with a monthly payroll of $ 3 , 500 , 000 . In 1941 , the drafting department had expanded to three buildings accommodating over 400 naval architects , engineers and draftsmen . The hospital had 584 beds . In 1969 the Navy transferred its ( Vietnam War ) Brown Water Navy Riverine Training Forces from Coronado , California to Mare Island . Swift Boats ( Patrol Craft Fast - PCF ) , and PBRs ( Patrol Boat River ) conducted boat operations throughout the currently named Napa - Sonoma Marshes State Wildlife Area , on the north and west portions of Mare Island . Mare Island Naval Base was deactivated during the 1995 cycle of US base closures , but the US Navy Reserves still have access to the water portions of the State Wildlife Area for any riverine warfare training being conducted from their new base in Sacramento , California . During the latter years of Mare Island ' s military use , US Marines were trained for Security Management and Security Force Operations , including ; F . A . S . T . ( Fleet Anti - Terrorism Team ) , Security Guards , and Security Force Reaction Forces . Restoration and reuse . In 1993 Congress approved the findings of the Base Realignment and Closure report , leading to the closure of Mare Island Naval Shipyard . The shipyard had long been the economic engine of the city of Vallejo , having reached an employment peak of 40 , 000 workers during World War II , and even employing 10 , 000 workers after scaling back in 1988 . When Congress ordered the base closure , the shipyard employed 5 , 800 workers . The vision of rebuilding Mare Island as a vital place where people lived and worked was a key goal in the base conversion planning process undertaken by the city of Vallejo in the early 1990s . Preservation of many of Mare Island ’ s 661 structures and other cultural resources was an additional factor in the planning process . As the oldest shipyard and naval facility on the West Coast , the shipyard earned a National Historic Landmark designation by the federal government in 1975 . In 1979 California listed the entire naval base as a State Historical Landmark . In 1999 the city of Vallejo added Mare Island to the National Register of Historic Districts with 42 individual city landmarks . Finally , as with any restoration of an industrial , brownfield landscape , both city and government agencies required environmental review , toxics removal , and soil mediation before any new development and reuse . In 1998 , Vallejo contracted with Lennar Mare Island LLC to develop the island ’ s into a multi - use community . Lennar contracted the Sausalito - based SWA Group to provide a Master Development Plan for Vallejo , additional historical research and landscape architectural services . The final land - use plan SWA submitted to Vallejo in 2005 divided Mare Island into 13 zones , including a university district , and industrial zone , historic core , and residential neighborhoods . In addition , 78 % of the island was set aside for wildlife habitat and wetlands , parkland and open space , and dredge ponds . SWA ’ s site plan began with the island ’ s grid of small , tree - lined streets and extended them so that they terminate in dramatic views of the bay and river and a new public waterfront . The historic core was repurposed as a new town center with retail , entertainment attractions , and additional , higher - density housing . Other improvements included a new grove of Canary Island Palm trees and London Plane trees along the G Street corridor , one of two entry points on the island . This feature enhances a visitor ’ s sense of arrival and frames the long view of Mt . Tamalpais across the San Pablo Bay . In 2007 Lennar finished construction on three new residential neighborhoods . Farragut Village , with 277 new homes in a site layout and landscape pattern designed by SWA Group , was the first completed neighborhood . Additional neighborhoods include Coral Sea and Kirkland Isle II . When all construction is complete , Mare Island will have 1 , 400 homes and condos , plus of commercial , retail , entertainment , and industrial space . Mare Island ’ s new residents petitioned Lennar Corp . and the city of Vallejo to drop the dredge ponds , whose role had been to collect silt , drainage , and stormwater from the Napa River and the Bay , and instead restore that acreage to wetlands . The city and the developer agreed , and in January 2006 , the land use plan was amended to add the Mare Island Shoreline Heritage Preserve . An advisory board was appointed by the city to restore the site into publicly accessible parkland . Overall , the conversion and reuse of Mare Island will result in the of protected tidal and nontidal wetlands providing wintering habitat for thousands of shorebirds and waterfowl . During the 2008 migrating season , thousands of people attended the three - day San Francisco Bay Flyway Festival in February on Mare Island . The event , which included an art show , exhibitors , and music , marked the annual return of more than a million shorebirds , ducks , geese , and hawks to the Bay Area . Access . Mare Island is accessed by State Route 37 on its north side , as well as by Interstate 80 via the Mare Island Causeway and Tennessee Street , a designated route . Mare Island is the location of Touro University California , the US Forest Service Pacific Southwest Regional Office , and the administrative offices of the Vallejo City Unified School District . For information on visiting Mare Island , see : For information on the Historic Nature of Vallejo , see :