Mare Island

Mare Island

Aerial photo of the southern part of Mare Island
Mare Island Show map of San Francisco Bay Area Mare Island Show map of California Mare Island Show map of the United States
Geography
Location	Northern California
Coordinates	38°05′43″N 122°16′41″W / 38.095254°N 122.278004°W / 38.095254; -122.278004
Adjacent to	San Francisco Bay
Administration
United States
State	California
County	Solano
City	Vallejo

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.