Mare Island, near the city of Vallejo, was the site of the first naval base in California. The Napa River forms the eastern side of the island as the river enters the Carquinez Strait at its juncture with the east side of San Pablo Bay. In 1850, Commodore John Drake Sloat, in charge of a commission to find a California naval base, recommended the island across the Napa River from the settlement of Vallejo, it being "free from ocean gales and from floods and freshets."