San Francisco Bay Metro Area

The watershed provides a primary source of drinking water for 25 million Californians, irrigation for 7,000 square miles of agriculture, and includes important economic resources such as California’s water supply infrastructure, ports, deepwater shipping channels, major highway and railroad corridors, and energy lines.

The first recorded European sighting of San Francisco Bay was in 1769 when Spanish explorer Gaspar de Portola observed it from the summit of Sweeny Ridge. Europeans first entered the bay in 1775 when Juan de Ayala’s explorations party visited and began mapping the bay. In 1776 the Spanish settled at the site of present-day San Francisco, and in the 1820’s whalers arrived. Following California’s annexation to the US in 1848, San Francisco became the center of American settlement in the Far West. The discovery of gold in the Sierra Nevada foothills in 1849 brought over 750 ships to San Francisco Bay that year, many of which were abandoned in the shallows, their remains now resting beneath the city’s financial district. The Gold Rush brought merchants, laborers, and craftspeople from around the world, and the bay became a hotspot for trading California grain and cowhides for goods from the eastern and northwestern US and Europe.

Significant sedimentation from mining and deliberate filling of many wetland areas and inlets in the bay reduced the size of the bay by about one third since the mid 19th century. Many of those filled-in areas have experienced devastating damage due to liquefaction of fill soil during earthquakes. Today San Francisco Bay is home to some of the densest industrial production and urban settlement in the country, with a population of about 8 million people in the Bay Area.

San Francisco Bay is a designated Ramsar Wetland of International Importance, and the bay and delta are some of California’s most critical habitats. Species such as the Sungeness crab, California halibut, and Pacific salmon rely on the bay as a nursery, while the Bay Area’s salt marshes are some of the few remaining salt marshes in California and support several endangered species. The bay is also a key link in the Pacific Flyway, the West Coast’s major route for migratory birds.

The bay is a popular recreation area known for sailing, yachting, and kayaking, with the latter taking advantage of the growing network for launching sites along the San Francisco Bay Area Water Trail. The Bay Area is home to one of the world’s largest urban parks and one of the most visited units of the National Park system, Golden Gate National Recreation Area. San Francisco also contains more than 220 city parks, making it a great place to enjoy the outdoors.