Contact Us

Mapping the Bay

SF Bay Area

The San Francisco Bay Area is composed of nine counties: Alameda, Contra Costa, Marin, Napa, San Mateo, Santa Clara, Solano, Sonoma, and San Francisco. The San Francisco Bay is the largest estuary on the west coast of North America and it is made up of four smaller bays: Suisun Bay, San Pablo Bay, Central Bay and the South Bay.

Spanish exploration and colonization

At its founding Yerba Buena was the remote northernmost outpost of a vast Spanish empire in the Americas. The walled presidio compound manned by a small garrison of soldiers secured the Spanish claim to San Francisco Bay. It was established in 1776 to block Russian and English incursions into northern California.

Default
Plano del puerto de Sn. Francisco, situado por los 37. grs. 53 mins. de latitud septentrional, y por 17. grs. 10. mins. de longitud occidental del puerto de Sn. Blas: registrado por el paquebot de S.M. el Sn. Carlos al mando de Dn. Juan Manuel de Ayala, Teniente de Fragata de la Real (Real) Armada.
1776
Default
Plano del puerto de Sn. Francisco, situado en la costa septentrional de California
1779

Ranchos

The Spanish and Mexican governments made about 300 land grants in California between 1784 and 1846, so called Rancho grants. The ranchos established permanent land-use patterns. The rancho boundaries became the basis for California's land survey system, and are found on modern maps and land titles. The "rancheros" (rancho owners) patterned themselves after the landed gentry of New Spain and chiefly raised cattle and sheep.

Default
Plat of the Northern Part of the Rancho San Antonio finally confirmed to Vicente and Domingo Peralta
1859
Default
Plat of the Rancho San Antonio : Alameda County, Calif.
186-?

Transportation

Bay area highways and public transit systems are more crowded than ever, Will we solve the area’s transportation challenges in the future — or will things only get worse?

Default
SFBay Highways-01
2016
Default
Megaregion Early Morning Commute 6:00 am or earlier
2016
Default
BART system map effective May 2018
SF Bay Area

Geology

The different tectonic forces in the Bay Area have caused the rock composition to be varied and its compositions is termed the Franciscan Complex. The below maps show different geologic aspects of the Bay Area.

Default
Map of the region adjacent to the Bay of San Francisco
1873
Default
Bay Area by Sentinel-2
2019
Default
Open-File Report 2006-1037 Sheet 1 (of 2) v.1.1 Quaternary Deposits
2006

Ecology

Until the 1850s San Francisco Bay was navigable as far south as San Jose. Then hydraulic fracturing released massive amounts of sediment from the rivers. The sediment settled in parts of San Francisco Bay which had little or no current. Later, wetlands and inlets were deliberately filled in and often built on, reducing the Bay's original size by as much as one third.

Default
San Francisco Estuary Historical
2010
Default
Shoreline Areas Vulnerable to Sea Level Rise: 2040-2060
2009

Sources