I currently live in NW Arkansas. In addition to the Buffalo and Elk, if you are in north Arkansas or southern Missouri I would also recommend:
Current River (MO)
Elevenpoint River (MO) - upstream of Greer Spring Branch
Kings River (AR)
North Fork (MO)
These are some prime smallie rivers. Not really hotspotting, because I am sure not many will ever venture to these parts but I assure you it is worth a vacation. The Elevenpoint is my favorite as it offers a diversity of species. Great warm water fishing above Greer Spring and trophy cold water fishing downstream.