Mare Island

Mare Island
Stitched aerial photos of the southern part of Mare Island
Mare Island
Mare Island
Mare Island
Geography
LocationNorthern California
Coordinates38°05′43″N 122°16′41″W / 38.095254°N 122.278004°W / 38.095254; -122.278004
Adjacent toSan Francisco Bay
Administration
State California
CountySolano
CityVallejo

Mare Island (Spanish: Isla de la Yegua) 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. Mare Island is a peninsula, as 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 3.5 miles (5.6 km) long and a mile wide.