{"nrhp_refnum":"77001487","name":"Colvin Run Mill","other_names":[],"category":"building","location":{"address":"S of Great Falls at 10017 Colvin Run Rd.","address_restricted":false,"city":"Great Falls","county":"Fairfax (city and county)","state":"VA","lat":38.96838633050004,"lon":-77.29264073288232,"geom_source":"nps_gis"},"listed_date":"1977-08-16","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Agriculture"],"significance_levels":["state"],"summary":{"what_it_is":"A four-story brick and frame grist mill built about 1810-1820 near Great Falls, Fairfax County, Virginia, on Colvin Run Road. It was restored between 1969 and 1975 and sits on a park site with a miller's house, dairy shed and moved general store.","why_significant":"The mill was built according to the milling principles of inventor Oliver Evans, whose continuous, automated process helped bring the production line to America. It represents the merchant and neighborhood milling that was central to Northern Virginia's agriculture and economy. Its careful restoration won architectural preservation awards in 1973 and 1975.","narrative":"Colvin Run Mill is a four-story brick and frame grist mill near Great Falls, Fairfax County, Virginia, built between about 1810 and 1820. Its machinery follows the design of Oliver Evans, who devised a continuous, automated system moving grain and meal by conveyor belts, buckets and hoists, all driven by an overshot waterwheel. Over its history the mill served local farmers and later became one of the area's earliest roller mills under the Millard family, who ran it until 1934. Relocation of Route 7 cut off its water supply, and the mill declined until the Fairfax County Park Authority acquired it in 1965. Restoration from 1969 to 1975 involved replacing about 75,000 bricks, stabilizing the foundation and rebuilding the millrace. The park also includes a miller's house, a dairy shed used as a carpentry shop, and a moved c. 1890 general store. The restoration earned architectural awards in 1973 and 1975.","period_of_significance":"1800-1899, 1900-","architect_builder":"unknown","architectural_style":null,"criteria":[],"status_note":"Restored 1969-1975 and in public park and museum use; condition listed as excellent. The miller's house hosts exhibitions, the dairy shed serves as a carpentry shop, and the general store is a museum and functioning post office.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:51:56.555126-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/75/6804/41680475/content/electronic-records/rg-079/NPS_VA/77001487.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/77001487/f1c4b8e665-800.webp","url_1600":"https://nationalhistoricalregister.com/media/77001487/f1c4b8e665-1600.webp","licence":"CC BY-SA 3.0","author":"Joe Ravi","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Colvin_Run_Mill.jpg\" rel=\"noopener\">Joe Ravi</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:Colvin_Run_Mill.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/41680475","wikipedia":"https://en.wikipedia.org/wiki/Colvin_Run_Mill","wikidata":"https://www.wikidata.org/wiki/Q5150311"},"indexable":true,"url":"https://nationalhistoricalregister.com/virginia/fairfax/colvin-run-mill-77001487/"}