I have a car that was jacked up thinking the frame was boxed and bent the side frame rail a while back. Is this a simple fix for a frame shop to pull it back down and straighten the rail out again?

Did it bend the entire rail or just "curl" the lower part? If the lower part is just curled, I wouldn't worry. If the whole rail is bent, A frame shop should have no problem getting it straight...

More like a curl around where the floor jack went up, the section is about 10". It only bugs me because looking at the car in profile I can see it. Plus if I ever took the car apart it's something I'd want fixed while it's in one piece.