Three states including Georgia, right? That's the only way to arrive at three. I just saw the episode that guest starred Cale Yarborough and it has Roscoe tricking the Dukes into crossing the State line which is a violation of parole. It seems to imply that Hazzard borders at least one state otherwise Roscoe wouldn't have jurisdiction, right?
Theoretically, Roscoe wouldn't have jurisdiction if the Dukes left Hazzard County but remained in their home state. (Since sheriffs are for counties.)
And, I believe, southern states call them "parishes" and not counties.