Built in 1913 for San Miguel County by the Missouri Valley Bridge and Iron Company, Kearny's Gap Bridge is 62 feet long and 16 feet wide. It is a free-span, steel, subdivided Warren pony truss bridge, a design recognizable by major cross-bracing along each side of the structure. The Warren Truss design was patented in 1848, but its use was most popular between 1870-1900. A 1987 Department of Transportation survey reported that eight Warren Pony Truss bridges were still in service and identified Kearny's Gap Bridge as being of historical and engineering interest. The bridge was originally in service along State Highway NM 283, following the route of the Santa Fe Trail, southwest of Las Vegas, NM.