{"nrhp_refnum":"97001113","name":"Ridge Route, Old","other_names":["Ridge Route","Ridge Road","Tejon Route","Tejon-Castaic Ridge Road"],"category":"structure","location":{"address":"Along Old Ridge Rte., roughly bounded by Sandberg and Canton Canyon","address_restricted":false,"city":"Castaic","county":"Los Angeles County","state":"CA","lat":34.64774507650006,"lon":-118.70074160935377,"geom_source":"nps_gis"},"listed_date":"1997-09-25","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A 17.6-mile unbroken stretch of the original Ridge Route roadway in the Angeles National Forest near Castaic, Los Angeles County, California. It was built between 1914 and 1919 as an early state highway and paved with reinforced concrete.","why_significant":"It was the first direct automobile and truck route linking Los Angeles with northern California, and it drew heavy traffic, which supported trade, tourism and regional unity. It is also an example of early mountain highway engineering, using sweeping banked curves and deep road cuts such as the 110-foot-deep Swede's Cut.","narrative":"Winding 17.6 miles over ridges in the Angeles National Forest, the Old Ridge Route is a mountain highway opened in 1915 as one of California's first state highways. It was the first direct automobile and truck link between Los Angeles and the northern part of the state, and by 1919 it was paved with 20-foot-wide reinforced concrete. Engineers avoided canyon routes and instead climbed the ridgelines with banked curves and deep cuts, including the 110-foot Swede's Cut. Traffic grew from 776 vehicles a day in 1920 to 2,280 in 1925, and inns, a road camp and other roadside businesses lined the route. The road was bypassed in 1933 and became a quiet backcountry route. Much of the original concrete, culverts, curbing and right-of-way markers survive, along with ruins of five motor inns and a maintenance camp. Utility lines and pipelines have caused some damage. It was listed for its role in regional transportation and for its engineering.","period_of_significance":"1915-1933","architect_builder":"W. Lewis Clark and J.B. Woodson, Designers, California Division of Highways; Lee Moor Contracting Company, Builder, El Paso, Texas; Mahoney Brothers, Builder, San Francisco, California","architectural_style":"Other: Reinforced concrete road","criteria":["A","C"],"status_note":"Abandoned as a through highway in 1933; the roadway remains open for slow-speed public automobile travel, with sections of potholes and dirt, and most original engineering features in fair to good condition.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:27.709215-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/97001113.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/97001113/9ce7d69c5c-800.webp","url_1600":"https://nationalhistoricalregister.com/media/97001113/9ce7d69c5c-1600.webp","licence":"CC BY-SA 3.0","author":"Chris English","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Near_Pyramid_Reservoir,_CA,_The_Ridge_Route,_2011_-_panoramio.jpg\" rel=\"noopener\">Chris English</a>, <a href=\"https://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:Near_Pyramid_Reservoir,_CA,_The_Ridge_Route,_2011_-_panoramio.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123859455","wikipedia":"https://en.wikipedia.org/wiki/Ridge_Route","wikidata":"https://www.wikidata.org/wiki/Q19195"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/los-angeles-county/ridge-route-old-97001113/"}