State Road 51 (SR 51) is a north–south state highway in north Florida. Its northern terminus is along the overlap of US 41 and US 129. It runs southwards as the "secret" designation of US 129 to Live Oak, where it splits off and runs independently south to Steinhatchee. The Hal W. Adams Bridge carries it across the Suwannee River three miles (5 km) north of Mayo. County Road 51 runs north from US 41/129 and SR 6 in Jasper to the Georgia border.