where is mare island
Aerial photo of the southern part of Mare Island. Mare Island is a peninsula in the United States in the city of Vallejo, California, about 23 miles (37 km) 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.n 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.