islands. History The indigenous inhabitants of the San Francisco Bay are Ohlone. The first European to see San Francisco Bay is likely N. de Morena who was left at New Albion at Drakes Bay in Marin County, California, by Sir Francis Drake in 1579 and then walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769, when Spanish explorer Gaspar de Portolá, unable to find the Port of Monterey, continued north close to what is now Pacifica and reached the summit of the Sweeney Ridge, now marked as the place where he first sighted San Francisco Bay. Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called Drakes Bay. At the time, Drakes Bay went by the name Bahia de San Francisco and thus both bodies of water became associated with the name. Eventually, the larger, more important body of water fully appropriated the name San Francisco Bay. The first European to enter the bay is believed to have been the Spanish explorer Juan de Ayala, who passed through the Golden Gate on August 5, 1775, in his ship the San Carlos and moored in a bay of Angel Island now known as Ayala Cove. Ayala continued to explore the Bay area and the expedition's cartographer, José de Cañizares, gathered the information necessary to produce the first map of the San Francisco Bay Area. A number of place names survive (anglicized) from that first map, including Point Reyes, Angel Island, Farallon Islands and Alcatraz Island. The United States seized the region from Mexico during the Mexican–American War (1846–1848). On February 2, 1848, the Mexican province of Alta California was annexed to the United States with the signing of the Treaty of Guadalupe Hidalgo. A year and a half later, California requested to join the United States on December 3, 1849, and was accepted as the 31st State of the Union on September 9, 1850. In 1921, a tablet was dedicated by a group of men including Lewis Francis Byington, in downtown San Francisco, marking the site of the original shoreline. The tablet reads: "This tablet marks the shore line of San Francisco Bay at the time of the discovery of gold in California, January 24, 1848. Map reproduced above delineates old shore line. Placed by the Historic Landmarks committee,