{"nrhp_refnum":"99000631","name":"Petrified Sea Gardens","other_names":["Ritchie Park"],"category":"district","location":{"address":"42 Petrified Gardens Road","address_restricted":false,"city":"Saratoga Springs","county":"Saratoga County","state":"NY","lat":43.08312216500008,"lon":-73.84405515399999,"geom_source":"nps_gis"},"listed_date":"1999-01-20","is_nhl":true,"nhl_designated_date":"1999-01-20","areas_of_significance":["Science"],"significance_levels":["national"],"summary":{"what_it_is":"Petrified Sea Gardens is a 25-acre wooded park on Petrified Gardens Road, west of Saratoga Springs, Saratoga County, New York. It preserves exposed Cambrian-age stromatolite fossils in Hoyt Limestone, and the park was established by Robert Ritchie in 1924.","why_significant":"The nomination argues the site is where stromatolites were first recognized, described and interpreted in North America, resolving a century-long question about their origin. It is also tied to Winifred Goldring, first woman State Paleontologist of New York, who made the most thorough study of the site and identified the organisms that built them. The site remains a classic stromatolite locality used in geological education.","narrative":"Petrified Sea Gardens is a 25-acre wooded park west of Saratoga Springs, New York, where outcrops of Hoyt Limestone display stromatolites formed about 515 million years ago in a shallow Cambrian sea. These layered, cabbage-like structures were built by cyanobacteria, and glaciers later planed their tops to reveal the concentric layering. The fossils were first noted in 1825 by John Steele, and in 1883 James Hall named them Cryptozoon, the first stromatolites scientifically described in North America. Robert Ritchie, a stone mason and amateur geologist, uncovered the outcrop in 1922 and opened the park in 1924. In 1937 Winifred Goldring, New York's first woman State Paleontologist, published the most exhaustive study of the site and identified the organisms responsible. Living stromatolites studied in Australia in 1961 confirmed her interpretations. The site continues to serve school groups, students and professionals, and a non-profit group now operates it.","period_of_significance":"1825-1948","architect_builder":null,"architectural_style":null,"criteria":["A","B","D"],"status_note":"Operated as a public park and educational site by a non-profit group, Friends of Petrified Sea Gardens, with signage at the stromatolite exposure.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:50:38.631574-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/99000631_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/99000631/d76f641603-800.webp","url_1600":"https://nationalhistoricalregister.com/media/99000631/d76f641603-1600.webp","licence":"CC BY-SA 3.0","author":"Daniel Case","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Grotto_at_Petrified_Sea_Gardens.jpg\" rel=\"noopener\">Daniel Case</a>, <a href=\"http://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:Grotto_at_Petrified_Sea_Gardens.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75316057","wikipedia":"https://en.wikipedia.org/wiki/Petrified_Sea_Gardens","wikidata":"https://www.wikidata.org/wiki/Q7178807"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/saratoga-county/petrified-sea-gardens-99000631/"}