Chattanooga is just upstream from Nickajack Res. on the Tennessee River. Nickajack is a great place to fish and early October will have the fish coming out of deep water and using the grass beds in shallower water. You might also consider fishing below the Nickajack dam in the headwaters of Guntersville. This area is full of great fishing. My PB Largemouth and Smallmouths have come from here.
Good Luck!