The vast San Francisco Bay and Delta region of California is placed at the union of Sacramento and San Joaquin Rivers. It is often referred to as the San Francisco Bay estuary. Since the detection of gold in the Sierra Nevada foothills in 1848, this area has undergone rapid, large-scale, and permanent changes driven by population migration involved to the region's natural setting and economic opportunities. The consequent land use changes, particularly urbanization, have resulted in the loss of wetlands, alteration of freshwater inflows, contamination of water, sediments and biota, and declines of fish and wildlife species.


The U.S. Geological Survey (USGS) has maintained a broad program of multi-disciplinary research studies, both basic and useful, in the San Francisco Bay estuary and its watershed. The studies help us understand the point and impact of these changes, as they also help decision-makers use science to help mitigate adverse things. USGS studies often are conducted in cooperation with other Federal, State, and local agencies, and have been planned to increase our understanding of main issues. These issues include waste disposal, water flow management, harbor/channel dredging, wetland restoration, food web processes, exotic species impacts, natural hazards mitigation, and maintaining quality of life.

"Access USGS-San Francisco Bay & Delta" was created to help distribute this information via the World Wide Web. Here you will find examples of USGS publications, posters, maps, and other information on the San Francisco Bay & Delta region from many disciplines.