In 1931, SH-48 was greatly expanded. The route was extended northward to US-66 in Stroud. At its southern end, it was extended along a new alignment, which began at SH-19, present day SH-3, southeast of Ada and ran through Tishomingo and Madill to end at the Red River northwest of Denison, Texas, where it met Texas State Highway 91. Also that year, a second section of SH-48 was established, taking over a large portion of what was then SH-25; the remainder of the route was integrated into US-60.