DO NOT take AL9, it will take you over the hilliest, tightest, little curvy road in Alabama, ask me know I know. In fact Adam met his thick girl friend at the end of it one day.
we normally take I-20 to AL 21 (exit 185) through Anniston, nice and flat but it does go through town so you gotta deal with a few stop lights. I took Exit 184 last time and on paper it looks better but there's a pretty good hill for the trailer pullers that you'd probably rather avoid.
If you've never been there it's kinda weird getting to the park. You actually have to go through a neighborhood so don't freak out if you think you're lost or your GPS is going nuts..