High Quality Content by WIKIPEDIA articles! The Dumbarton Bridge is the southernmost of the highway bridges that span the San Francisco Bay in California. Carrying over 81,000 vehicles daily, it is also the shortest bridge across San Francisco Bay at 1.63 miles (8,600 feet / 2,622 m). Its eastern terminus is in Fremont, near Newark in the San Francisco Bay National Wildlife Refuge, and its western terminus is in Menlo Park. The bridge has three lanes in each direction, and features a separated bike/pedestrian lane on its south-facing side. Like the San Mateo Bridge to the north, power lines parallel the bridge across the bay.