Rancho Miramontes (also called Arroyo de los Pilarcitos) was a 4,424-acre (17.90 km2) Mexican land grant in present day San Mateo County, California given in 1841 by Governor Juan B. Alvarado to Juan Jose Candelario Miramontes. Arroyo de los Pilarcitos means "creek of little pillars." The grant extended along the Pacific coast from Pilarcitos Creek and present day Half Moon Bay south past Miramontes Point to Canada Verdes.
Juan Jose Candelario Miramontes (1789–1846), came to Monterey with his parents in 1797 as part of the first settlers in Branciforte at Santa Cruz. Candelario Miramontes was a military officer at the Presidio of San Francisco, and he married Maria Guadalupe Briones (1793–1895) in 1808. In 1841 Governor Alvarado granted the one square league Rancho Arroyo de Los Pilarcitos (later called Rancho San Benito) to Juan Jose Candelario Miramontes. Candelario Miramontes remained in San Francisco, and died there in 1846. His sons Jose Vicente Miramontes (1809–) and Rodolfo (1820–) took up residence on the rancho.
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by the Land Act of 1851, a claim for Rancho Miramontes was filed with the Public Land Commission in 1852, and the grant was patented to Juan Jose Candelario Miramontes in 1882.
James Johnston (1813–1879), came from Ohio and after making money in the gold fields, returned to San Francisco and acquired an interest in a saloon and began speculating in real estate. Johnston married Petra de Jara in 1852. In 1853, Johnston purchased 1,162 acres (4.70 km2) of Rancho Miramontes from the heirs of Candelario Miramontes. James invited his brothers, John, Thomas and William to settle on the San Mateo coast. The Johnston brothers continued to make additional purchases, and by 1859, the Johnston Ranch comprised about half of the original Rancho Miramontes.
- Ogden Hoffman, 1862, Reports of Land Cases Determined in the United States District Court for the Northern District of California, Numa Hubert, San Francisco
- Diseño del Rancho Arroyo de los Pilarcitos
- United States. District Court (California : Northern District) Land Case 269 ND
- Report of the Surveyor General 1844 - 1886
- The James Johnston House