{"nrhp_refnum":"90000409","name":"Pennsylvania Furnace Mansion","other_names":["Lyon Mansion"],"category":"building","location":{"address":"Off PA 45, S of Centre County line","address_restricted":false,"city":"Pennsylvania Furnace","county":"Huntingdon County","state":"PA","lat":40.70384400900008,"lon":-78.01286444499993,"geom_source":"nps_gis"},"listed_date":"1990-03-20","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A two-and-a-half to four-story L-shaped native limestone ironmaster's mansion associated with the Pennsylvania Furnace iron operation on the Huntingdon-Centre County line in Pennsylvania Furnace, Pennsylvania. It was built in 1834 for John Lyon.","why_significant":"The house is described as the largest of Huntingdon County's ironmasters' houses and one of the best preserved, retaining Federal period detail such as cast iron fireplace inserts, hand-made hardware, and a transom and sidelights. It is the only standing structure associated with the furnace and related forging operations, and it is regarded as a fine example of Federal style architecture in the county.","narrative":"Built in 1834 for ironmaster John Lyon, this L-shaped native limestone mansion stands at Pennsylvania Furnace, on the Huntingdon-Centre County line. Its three-and-a-half-story northeast front is strictly symmetrical, with a paneled entrance door framed by a transom and sidelights and three gable-roofed dormers. The rear ell rises to four stories on its southwest side, and a hip-roofed porch dating from about 1920 crosses the front. The house was occupied by three generations of the Lyon family, who owned and operated the furnace, which was founded in 1813 and used steam machinery from 1856 until its operation ceased in 1888. The mansion is the only standing structure associated with the furnace and its forging works. It is regarded as the largest and most architecturally detailed ironmaster's mansion in Huntingdon County, and as a fine example of Federal style architecture there. Its interior retains cast iron fireplace inserts and hand-made hardware.","period_of_significance":"1834-1888","architect_builder":null,"architectural_style":"Federal","criteria":["A","C"],"status_note":"The house retains most of its period detail; a one-story stuccoed addition on the northwest side was apparently added after 1962.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:35.963164-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/90000409.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/90000409/aefcca7fd8-800.webp","url_1600":"https://nationalhistoricalregister.com/media/90000409/aefcca7fd8-1600.webp","licence":"Public domain","author":"Jet Lowe","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Pennsylvania_Furnace_Mansion.jpg\" rel=\"noopener\">Jet Lowe</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Pennsylvania_Furnace_Mansion.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993061","wikipedia":"https://en.wikipedia.org/wiki/Pennsylvania_Furnace_Mansion","wikidata":"https://www.wikidata.org/wiki/Q7163730"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/huntingdon-county/pennsylvania-furnace-mansion-90000409/"}