Acorn, Arkansas is an unincorporated community in Polk County, Arkansas, United States, approximately 6 miles north of Mena. The town is located at the junction of U.S. Route 59, U.S. Route 71 and U.S. Route 270 in the northern part of the county. Though Acorn is only a three-way junction, it marks the end of three separate U.S. highway concurrencies: U.S. 59 & 71 from Texarkana, U.S. 59 & 270 from Heavener, Oklahoma, and U.S.