The Big Blue River Bridge is a National Register of Historic Places-listed bridge located in Fillmore County, Nebraska, near the village of Grafton. The bridge is one of two listed on the Register within Fillmore County, the other being the Deering Bridge. The bridge is a single-span, concrete, spandrel arch facility. The site was first designed by state engineers in 1917, and was constructed in 1918. At the time of the construction, the facility's architectural style was the main bridge design in the state. The bridge still retains all original building materials, and has only undergone slight maintenance since construction. The bridge carries Fillmore County Road 6 over the West Fork of the Big Blue River.