The route begins at US Highway 61 (US 61) and the Great River Road at Tuckertown and runs 8.03 miles (12.92 km) east to CR 903 at O'Donnell Bend at a levee along the Mississippi River.

The route is maintained by the Arkansas Department of Transportation (ArDOT).

Highway 120 begins at US 61 in eastern Mississippi County within the Arkansas Delta.

Highway 120 crosses Bear Bayou before terminating at County Road 903, which runs along a levee for the Canadian Reach of the Mississippi River.

Media related to Arkansas Highway 120 at Wikimedia Commons