{"nrhp_refnum":"90001633","name":"Thompson Mill","other_names":[],"category":"building","location":{"address":"Golf Course Rd. at Seidel Cr., Robeson Township","address_restricted":false,"city":"Gibraltar","county":"Berks County","state":"PA","lat":40.27778244250007,"lon":-75.86252703666678,"geom_source":"nps_gis"},"listed_date":"1990-11-08","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Engineering","Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A gristmill complex on Seidel's Creek on the edge of the village of Gibraltar in Robeson Township, Berks County, Pennsylvania, consisting of a frame and stone mill built around 1816, a stone farmhouse of about 1850, and a stone outdoor bakeoven of about 1850, with a dam, pond and race.","why_significant":"The complex is argued to be significant for its association with the county gristmill industry, as a representative example of mills that were part of family farms. The mill retains early interior technology, including a hurst frame, bottle-and-beam tentering and wooden power transmission, and its turned posts and moldings are described as unusual for a country mill. The property is also described as one of twelve surviving frame mills in the county gristmill survey.","narrative":"A gristmill on Seidel's Creek near the village of Gibraltar in Berks County, Pennsylvania, the complex dates its mill to about 1816 and its stone farmhouse and outdoor bakeoven to about 1850. The mill is a banked frame and stone building of 36 by 54 feet with frame additions on the west side, and it was built to work alongside the farm it served. Its interior keeps early milling technology, including a hurst frame with a stone floor, bottle-and-beam tentering with forged bray iron, and wooden pin gear and flat belt transmission. The mill is recorded as operating from the early nineteenth century into the twentieth, with the last miller working there from 1905 to 1950. Its turned posts and moldings are considered unusually refined for a country mill. The complex is one of twelve surviving frame mills identified in a county gristmill survey, and the property is regarded as a clear example of how farm mills functioned in the region.","period_of_significance":"1829-1939","architect_builder":null,"architectural_style":"vernacular","criteria":["A","C","D"],"status_note":"The mill interior is in only fair condition and none of the original millstones remain in place; the present owner has installed a steel overshot water wheel and restored the race.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:36.122465-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/90001633.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/90001633/9cce188b5d-800.webp","url_1600":"https://nationalhistoricalregister.com/media/90001633/9cce188b5d-1600.webp","licence":"CC BY-SA 3.0","author":"Shuvaev","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Thompson_Mill,_BerksCo_PA.JPG\" rel=\"noopener\">Shuvaev</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:Thompson_Mill,_BerksCo_PA.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992348","wikipedia":"https://en.wikipedia.org/wiki/Thompson_Mill","wikidata":"https://www.wikidata.org/wiki/Q7795754"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/berks-county/thompson-mill-90001633/"}