History prior to 1846
- The San Andreas Fault begins to form in the mid Cenozoic about 30 million years ago
- 9.5 million years ago, the Moraga Volcanics produces most of the lavas that underlie the East Bay ridges from present day Tilden Regional Park to Moraga
- During the Quaternary glaciation beginning 2.58 million years ago, the basin now filled by the bay was a large linear valley with small hills, similar to most of the valleys of the Coast Ranges. The rivers of the Central Valley ran out to sea through a canyon that is now the Golden Gate. As the ice sheets melted, sea level rose 300 feet (91 m) over 4,000 years, and the valley filled with water from the Pacific.
- Evidence of human occupation of California dates from at least 17,000 BCE.
- The Ohlone people (pictured) inhabit the Bay Area region as early as 6,000 year ago, with a 1770 estimated population of 10,000–20,000
- The Coast Miwok inhabit the Sonoma region as early as 4,000 years ago, with a 1770 estimated population of 2,000
- The Patwin people inhabit the northern Bay region as early as early as 1,500 years ago, with a 1770 estimated population of 12,000
- The Bay Miwok inhabit the region that is now Contra Costa County, with a 1770 estimated population of approximately 1,700
- In 1539, Juan Rodríguez Cabrillo lands on islands off the coast of California, and names them Farallones, Spanish for cliffs or small pointed islets
- On 13 November 1542, Juan Rodríguez Cabrillo sights a peninsula from his ship and names it "Cabo de Pinos", while missing the entrance to San Francisco Bay
- Francis Drake lands at what is now known as Drakes Bay in 1579 (pictured), and claims the land for England, as New Albion
- Las Californias is established in 1768 by
New Spain, encompassing the Bay Area - Gaspar de Portolà arrives in the Bay Area in 1769
- Mission San Francisco de Asís and El Presidio Real de San Francisco are founded in 1776 in Yerba Buena
- Baptisms of the Yelamu by Spanish missionaries begin in 1777
- La Misión Santa Clara de Thamien is established in 1777 on the Guadalupe River
- In 1786, Jean-François de Galaup, comte de Lapérouse sails to San Francisco and maps the Bay Area
- In 1792, British explorer George Vancouver stops in San Francisco, in part, according to his journal, to spy on the Spanish settlements in the area
- In 1804, The Bay Area is part of the newly created New Spain state of Alta California
- The Russian-American Company establishes Fort Ross (pictured) in 1812, in what is now Sonoma County
- In 1821, New Spain cedes Alta California, including the Bay Area, to the newly created
Mexican Empire - William A. Richardson (pictured) arrives in San Francisco in 1822, and in 1838 is given Rancho Saucelito in present day Marin County by Mexican Governor Juan Alvarado
- In 1823, the Bay Area, as part of Alta California, becomes part of the newly founded
United Mexican States - In 1836, a 6.8 Richter scale earthquake strikes in the East Bay, likely on the Hayward Fault
- In 1837, Antonio Ortega begins operating a pulqueria (tavern) north of San Francisco, on the former site of Mission San Francisco Solano
- In 1838, a 7.0 MLa earthquake strikes the Peninsula, on or near the San Andreas Fault, with a maximum Mercalli intensity of VIII (Severe)
