{"nrhp_refnum":"90000850","name":"Rock Mill","other_names":[],"category":"building","location":{"address":"Rock Mill Rd. on S bank of the Hocking R.","address_restricted":false,"city":"Lancaster","county":"Fairfield County","state":"OH","lat":39.74849514300007,"lon":-82.71307520499994,"geom_source":"nps_gis"},"listed_date":"1990-06-01","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A braced-frame grist mill built in 1824 on the edge of a sandstone gorge just below the upper falls of the Hocking River, in Bloom Township near Lancaster, Fairfield County, Ohio. The .76-acre parcel also holds the dam site, millrace and gorge features.","why_significant":"The nomination argues the mill represents the early 19th-century grist milling industry in Ohio and is the only remaining grist mill structure in Fairfield County. It is also one of few Ohio mills from the first half of the century and appears structurally unique, with its power and grinding levels built into the gorge. Its ruinous remains may yield information for industrial historians.","narrative":"Rock Mill is a grist mill built in 1824 on the rim of a sandstone gorge below the upper falls of the Hocking River, near Lancaster in Fairfield County, Ohio. Its hand-hewn oak frame, braced and joined with pegged mortise and tenon joints, rises three stories above the rim, with two more levels down in the gorge. A 26-foot overshot wheel once drove the machinery, fed by a dam, a millrace cut through solid rock and a forebay. The mill was remodeled in 1899 with a turbine, then steam power, and stopped milling around 1905, after which it held farm storage. It replaced a log mill of 1799, the first mill in the county. The mill is listed as the only surviving grist mill in Fairfield County and as an unusual design that places grinding and gearing levels in the gorge. Although the equipment is gone and the building is vacant and deteriorated, the framing, the race and the remains of the hursting frame still show how it worked.","period_of_significance":"1824-1904","architect_builder":"Unknown (built by a Mr. Barrett or Barnett, per the form)","architectural_style":"No style","criteria":["A","C","D"],"status_note":"Vacant and in deteriorated condition; the northwest corner is structurally unsound, though the interior framing and flooring are described as excellent.","vacant_flag":true,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:14.035423-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/90000850.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/90000850/fd0d8e585d-800.webp","url_1600":"https://nationalhistoricalregister.com/media/90000850/fd0d8e585d-1600.webp","licence":"CC BY-SA 4.0","author":"Sdenisky","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Rock_Mill_01.jpg\" rel=\"noopener\">Sdenisky</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:Rock_Mill_01.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71988233","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q112691186"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/fairfield-county/rock-mill-90000850/"}