I believe Gumdrop is known locally as Gum Log. You were probably fishing the Tugaloo Creek arm which is where I would go if I were to fish Hartwell for Crappie. You may have put in at the Franklin County Boat Ramp. If you go North from the ramp (not sure how far) there used to be some standing timber on the right side that held fish. Eventually you would come to the bridge and I believe that is Hwy 328 or Gum Log Road. It sounds like you were on them.