{"nrhp_refnum":"78000373","name":"Great Sierra Wagon Road","other_names":["Aspen Valley Road","Old Tioga Road"],"category":"structure","location":{"address":"N of Yosemite Village","address_restricted":false,"city":"Yosemite Valley","county":"Tuolumne County","state":"CA","lat":37.84704549150004,"lon":-119.77596170891249,"geom_source":"nps_gis"},"listed_date":"1978-08-25","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Engineering","Transportation"],"significance_levels":["local"],"summary":{"what_it_is":"A 17-3/4 mile surviving section of the Great Sierra Wagon Road (also called Aspen Valley Road or the Old Tioga Road) in Yosemite National Park, Tuolumne County, California, built in 1882 by a silver mining company.","why_significant":"The road is of local significance in engineering, industry and transportation. Its largely unaltered drywall masonry retaining walls and culverts, built by Chinese laborers, reflect the engineering. It is also tied to silver mining in the region and to opening Yosemite's high country to the public and early motor travel.","narrative":"This 17-3/4 mile stretch of the Great Sierra Wagon Road, also known as the Old Tioga Road, runs northeast from the western boundary of Yosemite National Park toward White Wolf Campground. A silver mining company built the road in 1882 to haul supplies to its mine on Tioga Hill. Surveyors H. B. Carpenter and H.P. Medlicott laid it out, and engineer Charles N. Barney directed construction. Chinese laborers, who made up a large share of the workforce, built drywall masonry retaining walls and culverts that remain in place. The mine failed soon after completion, and the road sat neglected until Stephen T. Mather acquired it in 1915 and deeded it to the government, and it opened to automobiles that July. A 1937 realignment bypassed Aspen Valley, leaving this section largely unchanged. The nomination cites its engineering, its link to mining, and its role in early motor access to the high country. Much of it is now closed to public vehicles.","period_of_significance":"1882, 1915","architect_builder":"Great Sierra Consolidated Silver Co.; surveyors H. B. Carpenter and H.P. Medlicott; engineer Charles N. Barney","architectural_style":null,"criteria":[],"status_note":"Condition listed as good. The section from Aspen Valley to White Wolf Campground is closed to all but National Park Service vehicles as a fire road; the western section is open as an access route for area property owners.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:31.981626-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/78000373.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/78000373/61f6116704-800.webp","url_1600":"https://nationalhistoricalregister.com/media/78000373/61f6116704-1600.webp","licence":"Public domain","author":"Grogan, Brian, creator","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:OLD_TIOGA_ROAD_VIEW,_NOW_ASPEN_VALLEY_ROAD._LOOKING_WSW._GIS-_N-37_48_26.4_-_W-119_46_53.5_-_Tioga_Road,_Between_Crane_Flat_and_Tioga_Pass,_Yosemite_Village,_Mariposa_County,_CA_HAER_CAL,22-YOSEM,6-32.tif\" rel=\"noopener\">Grogan, Brian, creator</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:OLD_TIOGA_ROAD_VIEW,_NOW_ASPEN_VALLEY_ROAD._LOOKING_WSW._GIS-_N-37_48_26.4_-_W-119_46_53.5_-_Tioga_Road,_Between_Crane_Flat_and_Tioga_Pass,_Yosemite_Village,_Mariposa_County,_CA_HAER_CAL,22-YOSEM,6-32.tif"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123862278","wikipedia":"https://en.wikipedia.org/wiki/Great_Sierra_Wagon_Road","wikidata":"https://www.wikidata.org/wiki/Q5599960"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/tuolumne-county/great-sierra-wagon-road-78000373/"}