EntityQ3470840· pop 22· linked from 149 articlesBlackhawkSign in to savecensus-designated place in Contra Costa County, California, United StatesConnectionsrace and ethnicity in the United States CensusEntitySan Mateo CountyEntityUnited States Census BureauEntitycensus-designated place in the United StatesEntity2010 United States CensusEntity2020 United States CensusEntity2000 United States CensusEntity1990 United States CensusEntityUnited StatesCountryCaliforniaEntityFloridaEntitySan FranciscoEntitymarriageEntitytime zoneEntitygeographic coordinate systemEntitySan JoseEntityU.S. stateEntityOaklandEntityDaylight saving timeConceptAfrican AmericansEntityCategoriesCensus-designated places in CaliforniaCensus-designated places in Contra Costa County, CaliforniaUnincorporated communities in CaliforniaUnincorporated communities in Contra Costa County, California