When complete, the Bay Trail will be a continuous 500-mile recreational corridor that will encircle the entire Bay Area, connecting communities to each other and to the Bay. It will link the shorelines of all nine counties in the Bay Area and 47 of its cities. To date, 330 miles of the Bay Trail, or more than 60 percent of its ultimate length, have been developed.

The Bay Trail provides easily accessible recreational opportunities for outdoor enthusiasts, including hikers, joggers, bicyclists and skaters. It also offers a setting for wildlife viewing and environmental education, and it increases public respect and appreciation for the Bay.

The Bay Trail also has important transportation benefits: it provides a commute alternative for cyclists, and it connects to numerous public transportation facilities, including ferry terminals, light-rail lines, bus stops and Caltrain, Amtrak, and BART stations. Also, the Bay Trail will eventually cross all the major toll bridges in the Bay Area.

The Bay Trail provides access to commercial, industrial and residential neighborhoods; points of historic, natural and cultural interest; recreational areas like beaches, marinas and fishing piers; and over 130 parks totaling 57,000 acres of open space. It passes through highly urbanized areas like downtown San Francisco as well as remote natural areas like the San Francisco Bay National Wildlife Refuge. Depending on the location of its segments, the Bay Trail consists of paved multi-use paths, dirt trails, bike lanes, sidewalks or signed bike routes.

Senate Bill 100, authored by Senator Bill Lockyer and passed into law in 1987 with the endorsement of the entire Bay Area legislative delegation, advanced the concept of a "Ring around the Bay." SB 100 directed the Association of Bay Area Governments (ABAG) to develop an alignment for the Bay Trail as well as funding and implementation plans.

Implementation of the Bay Trail is being coordinated by the Bay Trail Project, a nonprofit organization housed at ABAG. To carry out its mission, the Project raises funds for trail construction and maintenance, ensures consistency with the adopted Bay Trail Plan, provides technical assistance, enlists public participation in trail-related activities, and publicizes the Bay Trail and its benefits to the region.