SIOUX CITY, IOWA — Newmark Knight Frank (NKF) has brokered the sale of Southern Hills Mall in Sioux City for $55 million. The 571,465-square-foot enclosed regional mall is located directly off I-29. The property was constructed in 1980 and renovated in 2007. Anchor tenants include AMC Classic Southern Hills 12, Barnes & Noble, J.C. Penney, Scheels Sports, Sears and Younkers. Thomas Dobrowski and Jeffrey Miller of NKF brokered the transaction. The names of the buyer and seller were not disclosed.