Half Moon Bay is a coastal city in San Mateo County, California, United States. Its population was 11,324 as of the 2010 census. Immediately at the north of Half Moon Bay is the Pillar Point Harbor and the unincorporated community of Princeton-by-the-Sea. The urban area had a population of 20,713 at the same census.HistoryHalf Moon Bay began as a rural agriculture area, primarily used for grazing of cattle, horses, and oxen used by Mission San Francisco de Asis (established in June 1776). Following the secularization of the Mission, Tiburcio Vásquez received the Rancho Corral de Tierra Mexican land grant in 1839 and Candelario Miramontes was granted Rancho Miramontes (later known as Rancho San Benito) in 1841.The community began to develop in the 1840s as the first real town in San Mateo County. Known originally as San Benito, the town was renamed Spanishtown and attracted a thriving fishing industry in addition to its continued importance to coastal agriculture. Spanishtown became a racially diverse community, settled by Canadians, Chinese, English, Germans, Irish, Mexicans, Italians, Scots, Portuguese, and Pacific Islanders. Regular stagecoach service was established with San Mateo; coaches also served the communities of Purissima, Lobitos, and San Gregorio. Levy Brothers opened a department store in downtown Half Moon Bay. Spanishtown was officially renamed Half Moon Bay in 1874.