{"nrhp_refnum":"87000003","name":"Shannon-Williamson Ranch","other_names":["Williamson Ranch"],"category":"district","location":{"address":"RR 1/Lone Tree Way","address_restricted":false,"city":"Antioch","county":"Contra Costa County","state":"CA","lat":37.95246567400005,"lon":-121.76454988897211,"geom_source":"nps_gis"},"listed_date":"1987-01-29","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Agriculture","Exploration/Settlement","Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A 398-acre working farm complex on Lone Tree Way in Antioch, Contra Costa County, California, homesteaded in the late 1860s by Thomas Shannon and developed by William Williamson from 1895 to 1929. It includes a c. 1895-96 house, tank house, barns, granary, bunk house and other farm buildings.","why_significant":"The nomination argues it is the only 19th century farm complex in eastern Contra Costa County to survive intact, and it reflects the county's wheat and barley agriculture. The buildings keep their original fabric and late 1800s character, and the family has farmed the land for four generations. The house is an eclectic Italianate design with spindlework typical of rural housing of 1880-1900.","narrative":"This 398-acre farm on Lone Tree Way in Antioch began as a 160-acre homestead claimed by Irish immigrants Thomas and Mary Ann Shannon in 1867. They grew wheat, barley and hay. William Williamson, Mary Ann's son-in-law, bought the original acreage in 1888 and ran the farm until his death in 1929. After the original log cabin burned around 1894, he and his wife Elizabeth built the present house in two phases, c. 1895 and c. 1896. The complex also holds a tank house, granary, bunk house, cow and buggy barn, horse barn, hay barn, garage, cistern and the site of an early privy. Farm implements and furnishings from the late 1800s are stored in the barns. The property was listed because it is the only 19th century ranch complex in eastern Contra Costa County preserved intact, and it shows the grain-growing economy that once dominated the county. Descendants of the Shannons still own it.","period_of_significance":"c. 1895-1929","architect_builder":null,"architectural_style":"Eclectic Italianate style with free classic adaptation and spindlework","criteria":[],"status_note":"Occupied and in agricultural use. The house, tank house and garage are in excellent condition, the barns are weathered and in fair condition, and the bunk house is in poor condition. The nomination describes the property as threatened by development and road widening.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:26.874764-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/87000003.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/87000003/e97daed937-800.webp","url_1600":"https://nationalhistoricalregister.com/media/87000003/e97daed937-1600.webp","licence":"CC BY-SA 3.0","author":"Sanfranman59","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Shannon-Williamson_Ranch_(Antioch,_CA).JPG\" rel=\"noopener\">Sanfranman59</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Shannon-Williamson_Ranch_(Antioch,_CA).JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123858573","wikipedia":"https://en.wikipedia.org/wiki/Shannon-Williamson_Ranch","wikidata":"https://www.wikidata.org/wiki/Q7488813"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/contra-costa-county/shannon-williamson-ranch-87000003/"}