{"nrhp_refnum":"96001103","name":"State Highway Bridge 5 at Big Pine Creek","other_names":["FM 1510 Bridge at Big Pine Creek","Lr0045-15-089"],"category":"structure","location":{"address":"FM 1510, 1.4 mi. E of jct. with FM 38","address_restricted":false,"city":"Brookston","county":"Lamar County","state":"TX","lat":33.66108354700003,"lon":-95.67331931099994,"geom_source":"nps_gis"},"listed_date":"1996-10-10","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A single-span, 50-foot steel Warren pony truss highway bridge on FM 1510 over Big Pine Creek, near Brookston in Lamar County, Texas. It was built in 1920-1921 by Austin Brothers Bridge Company under contract with the Texas Highway Department and widened in 1935-1936.","why_significant":"The bridge is significant in engineering as an example of early highway department design and of the department's economical construction and maintenance practices during the Depression. It uses the THD T5 standard design with suspended floor beams, and it is one of only two bridges on the Texas state highway system to do so. Its 1930s widening with a wooden deck is a rare technique and is considered a historically significant alteration.","narrative":"This 50-foot steel Warren pony truss bridge carries FM 1510 over Big Pine Creek in Lamar County, Texas. Austin Brothers Bridge Company built it in 1920 and 1921 for the Texas Highway Department, using the department's T5 standard design. That design hangs its floor beams beneath the bottom chords, a layout later replaced by braced beams. Only four 50-foot examples of the design survive, and this bridge and its neighbor at High Creek are the only state highway bridges in Texas that still use suspended floor beams. In 1935 and 1936 the department widened the roadway from 15 to 21 feet. Crews lifted the truss, rebuilt the abutments and replaced the concrete deck with timber stringers and plank flooring, a materials-saving choice during the Depression. When US 82 was straightened in the late 1940s, the bridge was bypassed and now serves light local traffic. That low use likely explains why the wooden deck survives.","period_of_significance":"1920-1921; 1935-1936","architect_builder":"Bridge Designer: Texas Highway Department; Truss Fabricator: Austin Brothers Bridge Company of Dallas, Texas; Bridge Builder: Austin Brothers Bridge Company of Dallas, Texas","architectural_style":"Other: Warren pony truss bridge","criteria":["C"],"status_note":"Still in vehicular use on FM 1510 with its wooden deck intact; modern guardrails were added in the 1980s. Its 1995 sufficiency rating of 11.9 made it eligible for replacement, though no projects were planned.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:23.058216-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/37/9698/40969837/content/electronic-records/rg-079/NPS_TX/96001103.pdf"},"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/40969837","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q110001111"},"indexable":true,"url":"https://nationalhistoricalregister.com/texas/lamar-county/state-highway-bridge-5-at-big-pine-creek-96001103/"}