{"nrhp_refnum":"89000945","name":"Guerneville Bridge","other_names":["Russian River Bridge No. 20-91"],"category":"structure","location":{"address":"Rt. 116 over Russian River","address_restricted":false,"city":"Guerneville","county":"Sonoma County","state":"CA","lat":38.50102523400005,"lon":-122.99549078499996,"geom_source":"nps_gis"},"listed_date":"1989-08-04","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Entertainment/Recreation"],"significance_levels":["local"],"summary":{"what_it_is":"A 948-foot steel and reinforced concrete road bridge carrying State Highway 116 over the Russian River at Guerneville, Sonoma County, California. It was built in 1922 and is also known as Russian River Bridge No. 20-91.","why_significant":"The nomination argues the bridge is significant under Criterion A for its link to the Russian River summer resort area. It was the only practical auto access to the Guerneville resort segment, and it shaped the town's commerce and layout, with five roads converging at its north end. It is also described as the oldest auto bridge over the Russian River on a major road to the resorts.","narrative":"Carrying State Highway 116 across the Russian River at Guerneville, this 948-foot bridge was completed in 1922. It has 21 spans: three 180-foot pin-connected steel through trusses on concrete piers, flanked by seven approach spans on the south and eleven on the north, all built of reinforced concrete. A cantilevered sidewalk was added on the downstream side six years after construction. The bridge was listed for its role in the Russian River resort region. In the 1920s and 1930s, vacationers from San Francisco and Santa Rosa increasingly arrived by automobile, and this crossing was the only practical road access to the Guerneville resorts. Its north end meets five roads, which helped concentrate groceries, garages, restaurants and other businesses at the town's center. It was also part of a county highway program approved by voters in 1919. The designer is recorded as W. Lloyd Hook. Later changes, including skid rails and modern lighting, are described as minor.","period_of_significance":"1922-1939","architect_builder":"Hook, W. Lloyd","architectural_style":"Pratt through truss","criteria":["A"],"status_note":"Still carries Highway 116 traffic and pedestrians; the form says it retains a high degree of integrity, with minor alterations such as added skid rails, utility cables, modern street lamps and a chain-link fence.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:28.269697-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/89000945.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/89000945/b68410d823-800.webp","url_1600":"https://nationalhistoricalregister.com/media/89000945/b68410d823-1600.webp","licence":"CC BY-SA 4.0","author":"MahmoudHashemi","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Guerneville_-_Guerneville_Bridge_-_20190908130749.jpg\" rel=\"noopener\">MahmoudHashemi</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:Guerneville_-_Guerneville_Bridge_-_20190908130749.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123862074","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q58491943"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/sonoma-county/guerneville-bridge-89000945/"}