The San Mateo County Harbor District, which runs Pillar Point Harbor in Princeton and Oyster Point Marina/Park in South San Francisco, was created by a County election in 1933. It was originally formed to build a harbor at Redwood City, but the Great Depression intervened.

Coastsiders then pushed to get a breakwater built at Pillar Point for a harbor of refuge for the fishing fleet. The Army Corps of Engineers began work on this breakwater after World War II and finally completed it in 1961. The Johnson Pier, docks and 369 berths, and the inner breakwater were built during the 1970's and 1980's. Pillar Point remains a major commercial and sport fishing harbor on California's central coast, and is host to many public events including the annual Mavericks surfing competition, the July 4th fireworks display, and the Christmas boat decorating contest.

The District took over operation of Oyster Point Marina/Park from the City of South San Francisco in 1977. It then completed construction of docks and 589 berths, a new breakwater, and onshore facilities during the 1980's. The District is now diversifying this recreational marina by bringing in ferryboat service to the East Bay, dining cruises, marine educational programs, and cooperation with the City on area redevelopment.