Bridge No. 44, now known as the Bunton Branch Bridge, is located just north of Kyle on a north-south section of road that parallels Interstate 35, a remnant of the 1915 Austin-Aan Antonio post road. The bridge crosses Bunton Branch, an intermittent tributary of Plum Creek that runs in a southeast direction across Hays and Caldwell Counties. The creek has its headwaters east of Mountain City in Hays County and was named after the family of a signer of the Texas Declaration of Independence, Col. John W. Bunton.
The 42-foot long concrete structure was built in 1915 by J.N. George & Sons Construction Company as part of the first federal aid highway projects in Texas. The bridge is composed of a single closed-spandrel arch forty feet in length supported by reinforced concrete abutments. The bridge's deck, measuring 20 feet in width, is composed of concrete and carries one-lane traffic over an 18-foot wide roadway. Out of thirty-five bridges built within a distance spanning 78 miles, the Bunton Branch Bridge is the only known reinforced concrete arch bridge as part of this project.
The improvements made to the Austin-San Antonio Road (later state highway 2) and the construction of bridges like this one resulted in a wave of travel and tourism for central Texas. By the 1920s, State Highway 2 was one of the heaviest traveled
roads in the state. In the 1930s, the state highway department changed the alignment of the highway, abandoning the section of old post road over Bunton Branch Bridge. Today, this historic bridge is one of the few tangible links to this historic highway in Hays County.