{"nrhp_refnum":"06000527","name":"Lassen Volcanic National Park Highway Historic District","other_names":["NPS Route 1","Lassen Loop Highway","Lassen Peak Highway","State Route 89"],"category":"district","location":{"address":"NPS Route 1, CA 89","address_restricted":false,"city":"Mineral","county":"Shasta County","state":"CA","lat":40.518255419500065,"lon":-121.51413972246914,"geom_source":"nps_gis"},"listed_date":"2006-06-23","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Entertainment/Recreation","Architecture","Landscape Architecture","Community Planning and Development"],"significance_levels":["state","local"],"summary":{"what_it_is":"A 29.86-mile linear designed landscape and park road running between the southwest and northwest entrance stations of Lassen Volcanic National Park in Shasta and Tehama Counties, California, designed in the early 1920s as a recreational pleasure drive.","why_significant":"The nomination argues the highway is an intact example of early National Park Service road design. Its alignment, overlooks, culvert headwalls, bridge culverts, entrance pylons and northwest entrance station use native materials and naturalistic design to blend with the volcanic landscape. It reflects major construction by the National Park Service, the Bureau of Public Roads and the Civilian Conservation Corps.","narrative":"Lassen Volcanic National Park Highway is a 29.86-mile road linking the park's southwest and northwest entrances. It climbs from 6,646 feet to 8,511 feet near Lassen Peak, then descends toward Manzanita Lake, crossing geothermal areas, subalpine forests, meadows and lava fields. National Park Service engineers laid out the alignment in 1924-25 to show automobile tourists the park's most scenic and geologically interesting places, and the Bureau of Public Roads took over much of the construction after a 1926 agreement. Civilian Conservation Corps projects continued until 1941, and paving and widening followed between 1948 and 1951. Scenic pullouts, masonry culvert headwalls, bridge culverts, entrance pylons and the northwest entrance station were built from native materials to blend with the surroundings. Grades never exceed six percent. The road is listed as an intact early example of national park road design, and it remains the main way visitors experience the park.","period_of_significance":"1925-1941 and 1948-1951","architect_builder":"National Park Service engineers and landscape architects; Bureau of Public Roads","architectural_style":"Other: NPS Rustic","criteria":[],"status_note":"Still used as the primary touring route through the park; closed by snow from late October through mid-June.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:29.615279-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/06000527.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/06000527/55ee73afd1-800.webp","url_1600":"https://nationalhistoricalregister.com/media/06000527/55ee73afd1-1600.webp","licence":"Public domain","author":"National Park Service","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Lassen_Park_Highway.jpg\" rel=\"noopener\">National Park Service</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Lassen_Park_Highway.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123857804","wikipedia":"https://en.wikipedia.org/wiki/Lassen_Volcanic_National_Park_Highway_Historic_District","wikidata":"https://www.wikidata.org/wiki/Q6493975"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/shasta-county/lassen-volcanic-national-park-highway-historic-district-06000527/"}