{"nrhp_refnum":"91001538","name":"Heathcote-MacKenzie House","other_names":["Heritage House"],"category":"building","location":{"address":"4501 Pleasanton Ave.","address_restricted":false,"city":"Pleasanton","county":"Alameda County","state":"CA","lat":37.65999006900006,"lon":-121.88491409599999,"geom_source":"nps_gis"},"listed_date":"1991-10-29","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Entertainment/Recreation"],"significance_levels":["local"],"summary":{"what_it_is":"A one-and-a-half-story Craftsman bungalow at 4501 Pleasanton Avenue in Pleasanton, Alameda County, California, built about 1905 on the Pleasanton Fairgrounds on its original site.","why_significant":"The nomination argues the house was the center of historical horse racing activity in the Livermore-Amador Valley for over 75 years and is the sole remaining structure from the area's racing business. It also served as the office of the Fair Association and is one of very few Craftsman bungalows in the area.","narrative":"Built about 1905 on the grounds of what is now the Pleasanton Fairgrounds, this one-and-a-half-story Craftsman bungalow was constructed for Rodney G. MacKenzie, a wealthy Canadian harness racing enthusiast. He used it to entertain fellow Canadian racers who wintered their horses in the area, and their spending on hay, grain, labor and lodging boosted Pleasanton's small economy between 1895 and 1912. In 1912 MacKenzie helped form a Fair Association that held fairs and races on the site, and the house served as its office until 1970, after which it became a museum for a valley historical society. The wood-framed house has a gabled roof, clinker brick chimneys, a recessed dormer, French doors and a tile and brick porch with hand-carved pillars. Asbestos siding, probably added in the 1940s, covers the original wood. It is the only surviving structure from the area's racing business and one of few Craftsman bungalows nearby.","period_of_significance":"c. 1905 to 1941","architect_builder":null,"architectural_style":"Bungalow/Craftsman","criteria":["A"],"status_note":"Currently used as a government museum for a valley historical society; renovation work funded by state grants and local funds is complete.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:27.400024-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/91001538.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/91001538/01d2c0f1e1-800.webp","url_1600":"https://nationalhistoricalregister.com/media/91001538/01d2c0f1e1-1600.webp","licence":"CC BY-SA 4.0","author":"Cicinature","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Heritage_House.png\" rel=\"noopener\">Cicinature</a>, <a href=\"https://creativecommons.org/licenses/by-sa/4.0\" rel=\"license noopener\">CC BY-SA 4.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Heritage_House.png"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123858244","wikipedia":"https://en.wikipedia.org/wiki/Heathcote-MacKenzie_House","wikidata":"https://www.wikidata.org/wiki/Q133258231"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/alameda-county/heathcote-mackenzie-house-91001538/"}