{"nrhp_refnum":"91002039","name":"Farm Creek Section","other_names":["Farm Creek/Farmdale Geologic Exposure"],"category":"site","location":{"address":"S side of Farm Cr.","address_restricted":false,"city":"East Peoria","county":"Tazewell County","state":"IL","lat":40.67729430050005,"lon":-89.4898200830085,"geom_source":"nps_gis"},"listed_date":"1992-02-06","is_nhl":true,"nhl_designated_date":"1997-12-09","areas_of_significance":["Science"],"significance_levels":["national"],"summary":{"what_it_is":"A geological exposure about 100 feet high and 225 feet long in a stream bank cut into a hill on the south side of Farm Creek near East Peoria, Tazewell County, Illinois. It lies within the federally owned Farmdale Dam Flood Control Project and was first discovered in 1897.","why_significant":"The exposure played a key role in developing theories of Pleistocene continental glaciation, including multiple glaciations, interstadial climate changes, the origin of loess and buried soils. It is tied to geologist Frank Leverett, who discovered it in 1897. It remains a type reference section and may yield future research information.","narrative":"Farm Creek Section is a natural geological exposure in a stream bank on the south side of Farm Creek near East Peoria, Illinois. About 100 feet high and 225 feet long, it reveals layers of Pleistocene sediment, including loess, glacial till, outwash gravels and buried soils. Glacial geologist Frank Leverett discovered it in 1897 and described it in his monograph on the Illinois glacial lobe. The site helped settle a debate over whether ice retreats were brief or prolonged, informed the naming of the Sangamon Soil and the Peorian stage, and supplied evidence that loess was windblown. It serves as the type section for the Farmdalian Substage, Robein Silt, Morton Loess and Farmdale Soil. The exposure has changed little in nearly a century and remains a reference point for researchers and field trips. It sits within a federal flood control and recreation area and is reachable by an unpaved road.","period_of_significance":"1897-1941","architect_builder":null,"architectural_style":null,"criteria":["A","B","D"],"status_note":"Described as virtually unchanged since its discovery, readily accessible by vehicle or on foot, and still visited by geologists and students.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:35.076705-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/52/8916/28891652/content/electronic-records/rg-079/NPS_IL/91002039_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/91002039/38de39a439-800.webp","url_1600":"https://nationalhistoricalregister.com/media/91002039/38de39a439-1600.webp","licence":"CC0","author":"Ammodramus","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Farm_Creek_Section_series_2_b.jpg\" rel=\"noopener\">Ammodramus</a>, <a href=\"http://creativecommons.org/publicdomain/zero/1.0/deed.en\" rel=\"license noopener\">CC0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Farm_Creek_Section_series_2_b.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28891652","wikipedia":"https://en.wikipedia.org/wiki/Farm_Creek_Section","wikidata":"https://www.wikidata.org/wiki/Q5435493"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/tazewell-county/farm-creek-section-91002039/"}