{"nrhp_refnum":"78002480","name":"Meadowcroft Rockshelter","other_names":["36wh297"],"category":"site","location":{"address":"W of Avella","address_restricted":false,"city":"Avella","county":"Washington County","state":"PA","lat":40.286388099500044,"lon":-80.49111165197885,"geom_source":"nps_gis"},"listed_date":"1978-11-21","is_nhl":true,"nhl_designated_date":"2005-04-05","areas_of_significance":["Prehistoric"],"significance_levels":["national"],"summary":{"what_it_is":"Meadowcroft Rockshelter (site 36WH297) is a stratified, multi-component archaeological site in Avella, Washington County, Pennsylvania, formed beneath a sandstone cliff on the north bank of Cross Creek.","why_significant":"The site contains eleven well-defined stratigraphic units spanning about 15,000 years of intermittent occupation, representing all of the major cultural stages recognized in northeastern North America. Its early Paleo-Indian occupations are dated by radiocarbon, and the nomination argues it is the oldest well-dated site in eastern North America and one of the longest stratified occupational sequences in the Western Hemisphere's northern hemisphere.","narrative":"Meadowcroft Rockshelter is an archaeological site in Avella, Washington County, Pennsylvania, sheltered by an overhang of Morgantown-Connellsville sandstone on the north bank of Cross Creek. The rockshelter's ceiling has been eroding and migrating upward and cliffward over time, forming a re-entrant above a softer underlying shale. Excavations of its deposits, carried out in 1973 and 1974, isolated eleven distinct stratigraphic units. These layers record occupation spanning about 15,000 years, beginning around 13,000 B.C. with people who made prismatic blades, unifacial scrapers, bifaces and finely fluted knives. The site served as a base for hunting, collecting and food processing, drawing on the nearby Cross Creek Valley and uplands. Its sequence contains deposits from every major cultural period recognized in northeastern North America. Radiocarbon dating makes it the oldest well-dated site in eastern North America and one of the longest stratified occupation sequences in the Americas.","period_of_significance":null,"architect_builder":null,"architectural_style":null,"criteria":[],"status_note":null,"vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:29.907733-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/78002480.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/78002480/3f834f1e34-800.webp","url_1600":"https://nationalhistoricalregister.com/media/78002480/3f834f1e34-1600.webp","licence":"CC BY-SA 4.0","author":"Lee Paxton","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:MeadowcroftRockshelter.jpg\" rel=\"noopener\">Lee Paxton</a>, <a href=\"https://creativecommons.org/licenses/by-sa/4.0\" rel=\"license noopener\">CC BY-SA 4.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:MeadowcroftRockshelter.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994561","wikipedia":"https://en.wikipedia.org/wiki/Meadowcroft_Rockshelter","wikidata":"https://www.wikidata.org/wiki/Q1896118"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/washington-county/meadowcroft-rockshelter-78002480/"}