Bay is a shallow, productive estuary through which water draining from approximately forty percent of California
, flowing in the Sacramento
and San Joaquin rivers from the Sierra Nevada
mountains, enters the Pacific Ocean. Specifically, both rivers flow into Suisun Bay, which flows through the Carquinez Strait to meet with the Napa River
at the entrance to San Pablo
Bay, which connects at its south end to San Francisco Bay. However, the entire group of interconnected bays is often referred to as "San Francisco Bay".
San Francisco Bay is located in the U.S. state of California, surrounded by a contiguous region known as the San Francisco Bay Area dominated by the large cities San Francisco, Oakland
, and San Jose
. The waterway entrance to San Francisco Bay from the Pacific Ocean is called Golden Gate. Across the strait spans the Golden Gate Bridge
The Bay covers somewhere between 400 and 1,600 square miles (1,040 to 4,160 square kilometers), depending on which sub-bays (such as San Pablo Bay), estuaries, wetlands, and so on are included in the measurement.The main part of the Bay measures 3 to 12 miles (5 to 20 km) wide east-to-west and somewhere between 48 miles (77 km)1 and 60 miles (97 km)2 north-to-south. It is the largest Pacific estuary in North or South America
San Francisco Bay is a mecca for sailors (boats, as well as windsurfing and kitesurfing), due to consistent strong westerly/northwesterly thermally-generated winds (Beaufort force 6 (15-25 knots) is common on summer afternoons) and protection from large open ocean swells.
Yachting and yacht racing are popular pastimes and the San Francisco Bay Area is home to many of the World
's top sailors. A shoreline bicycle and pedestrian trail known as the San Francisco Bay Trail encircles the edge of the bay. Parks and protected areas around the bay include Eden Landing Ecological Reserve, Hayward
Regional Shoreline, Don Edwards
San Francisco Bay National Wildlife Refuge and César Chávez Park.
The San Francisco Bay Area Water Trail is a planned system of designated trailheads designed to improve non-motorized small boat access to the bay. The California Coastal Conservancy approved funding in March 2011 to begin implementation of the water trail.Kitesurfing and wind surfing are also popular in the bay.