{"nrhp_refnum":"75001315","name":"Harpersfield Covered Bridge","other_names":[],"category":"structure","location":{"address":"County Road 154 over the Grand River","address_restricted":false,"city":"Harpersfield","county":"Ashtabula County","state":"OH","lat":41.756288264000034,"lon":-80.94424287799995,"geom_source":"nps_gis"},"listed_date":"1975-11-03","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["local"],"summary":{"what_it_is":"A two-span wooden Howe truss covered bridge carrying county road 154 over the Grand River at Harpersfield, Ashtabula County, Ohio, built in 1873 and said to be the work of a carpenter named Potter.","why_significant":"At 243 feet, it is the longest covered bridge remaining in Ohio, at a time when covered bridges over 500 feet were once not uncommon. It also illustrates the Howe truss, patented in 1840, which introduced iron rods as vertical members.","narrative":"Spanning the Grand River at Harpersfield in Ashtabula County, this two-span wooden covered bridge was built in 1873 on the Howe truss plan. At 243 feet, it is the longest covered bridge remaining in Ohio, where spans over 500 feet were once not unusual. The Howe design, patented in 1840, used wooden braces in X shapes with iron rod verticals that could be tightened to correct sagging. The bridge has high vertical siding, a shingle roof, and has always been left unpainted. The great flood of 1913 cut a new channel around the north end, so a steel truss span was added and the north abutment and center pier were rebuilt in concrete; the south abutment remains original cut stone. Heavy snow collapsed the roof in 1962-63, and the siding was replaced in 1963. The road became part of the state highway system in the early 1930s and returned to county control in 1962.","period_of_significance":"1873","architect_builder":"Carpenter named Potter (said to have built it); Howe truss patented by William Howe","architectural_style":"Howe truss covered bridge","criteria":[],"status_note":"Listed in good condition, original site, altered; owned by Ashtabula County. The county was considering closing it to traffic and turning it over to the adjacent county park system.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:09.965753-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/75001315.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/75001315/763b1f1028-800.webp","url_1600":"https://nationalhistoricalregister.com/media/75001315/763b1f1028-1600.webp","licence":"CC BY-SA 2.5","author":"Photo by and ©2003 Homefryes","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Harpersfield_(Ashtabula_County,_Ohio)_Covered_Bridge_1.jpg\" rel=\"noopener\">Photo by and ©2003 Homefryes</a>, <a href=\"https://creativecommons.org/licenses/by-sa/2.5\" rel=\"license noopener\">CC BY-SA 2.5</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Harpersfield_(Ashtabula_County,_Ohio)_Covered_Bridge_1.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71986693","wikipedia":"https://en.wikipedia.org/wiki/Harpersfield_Covered_Bridge","wikidata":"https://www.wikidata.org/wiki/Q5663518"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/ashtabula-county/harpersfield-covered-bridge-75001315/"}