By December 1960, approximately of US 66 had been rebuilt into the first section of I-40 to open in Arizona, and a further of US 66 was also undergoing conversion into I-40. By October 1962, of US 66 between Williams and Flagstaff was being rebuilt into parts of I-40. The new section was completed and opened to traffic later the same year. In 1966, a new four-lane steel bridge was opened over the Colorado River, replacing the Red Rock Bridge. US 66 was moved onto the new bridge, running concurrently with the new I-40 across the river. The Red Rock Bridge was closed following the opening of the new bridge and sat completely abandoned for over a decade. Unlike the Old Trails Bridge, the Red Rock Bridge would never be repurposed. In 1976, the bridge was entirely dismantled. Today, only concrete pilings remain where the bridge once stood.