{"nrhp_refnum":"71000525","name":"Harmony Mill No. 3","other_names":["Mastodon Mill","See also: Harmony Mills Historic District"],"category":"building","location":{"address":"100 N. Mohawk St.","address_restricted":false,"city":"Cohoes","county":"Albany County","state":"NY","lat":42.78167489900005,"lon":-73.70493092499999,"geom_source":"nps_gis"},"listed_date":"1971-02-18","is_nhl":true,"nhl_designated_date":"1999-01-20","areas_of_significance":["Industry","Architecture"],"significance_levels":["national"],"summary":{"what_it_is":"Harmony Mill No. 3, known as the \"Mastodon Mill,\" is a brick textile mill at 100 North Mohawk Street in Cohoes, Albany County, New York. The north section was built 1866-68 and a south addition was begun in 1871.","why_significant":"The nomination cites the mill's skillful architectural treatment, notably its mansard roof and twin towers, which make it a well-scaled part of the Harmony complex of mills, workers' houses and commercial buildings. It also reflects the Harmony Manufacturing Company, which played an extremely important role in Cohoes's economic history. The mill got its nickname from a mastodon skeleton found during foundation excavation.","narrative":"Harmony Mill No. 3 is a large red brick textile mill at 100 North Mohawk Street in Cohoes, New York, popularly called the \"Mastodon Mill.\" Its north section was built between 1866 and 1868, and a southern addition, planned as part of the original scheme, was begun in 1871. D.H. Van Auken, a Cohoes architect and engineer who also served the Cohoes Company, designed it. The building rises four full stories plus a fifth under a mansard roof, with brick bearing walls, cast iron columns, wooden floor joists and hooded dormers. Twin six-story towers with mansard caps and cast iron grillwork mark the central block. The mill was valued for its skillful facade and its place within the Harmony complex of mills, workers' houses and commercial buildings, built by a company incorporated in 1836 that shaped Cohoes's economy. The nickname comes from a mastodon skeleton uncovered while digging the foundations.","period_of_significance":"19th Century (specific dates 1866-68; 1871-72)","architect_builder":"D.H. Van Auken","architectural_style":"Mansard roof (Second Empire-style features); style not formally named in the form","criteria":[],"status_note":"Listed in good condition, unaltered, on its original site, occupied and in industrial use. Exterior access is unrestricted and interior access is restricted.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:50:39.584262-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/71000525.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/71000525/8778700e83-800.webp","url_1600":"https://nationalhistoricalregister.com/media/71000525/8778700e83-1600.webp","licence":"Public domain","author":"Unknown authorUnknown author","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:HarmonyMills_HAER_cropped.jpg\" rel=\"noopener\">Unknown authorUnknown author</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:HarmonyMills_HAER_cropped.jpg"},"district":{"nrhp_refnum":"78003151","name":"Harmony Mill Historic District","url":"https://nationalhistoricalregister.com/districts/new-york/harmony-mill-historic-district-78003151/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75316241","wikipedia":"https://en.wikipedia.org/wiki/Harmony_Mill_No._3","wikidata":"https://www.wikidata.org/wiki/Q5659577"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/albany-county/harmony-mill-no-3-71000525/"}