San Francisco is a large town in Dawn 2055. San Francisco and its ruins are claimed by the following gangs: Phoenix Coalition, El Diablo Grande, and the Lost Souls Syndicate, which only has claims in the outskirts. Although it isn't as big as Los Angeles it is still the second largest ruins area.
As mentioned above, multiple gangs claim the area but the bay itself is under the control of The Phoenix Coalition. The factions controlling the area mostly require people to enter with permission.
Somewhat similarly to Los Angeles, scavenging in San Fransisco is heavily valuable, with a very large variety of ruins. The main issue is that much of it is spread out and without bridges, so making your way around can be difficult. In addition, Phoenix Coalition bars people from scavenging.