Sterling Street Substation, Near corner of Harrison & Second Streets, San Francisco, San Francisco County, CA

Significance: This building was constructed as an electrical substation for the Key System trains that originally ran on the Bay Bridge, from Oakland to the Transbay Terminal in San Francisco. It was a vital component of the Bay Bridge. Although electric trains no longer run on the bridge, this building has retained its original use as an electrical substation and its association with the historic bridge. The concrete building (excluding the adjacent modern building and wheelchair ramp) also possesses a high degree of integrity, with alterations limited to a small canopy on the east side and installation of two ventilation louvers on the south wall. The building is therefore eligible for National Register listing as a contributing component of the Bay Bridge.
Survey number: HAER CA-228
Building/structure dates: 1937 Initial Construction