Try antennaweb.org for specifics/maps on coverage you can search individually by channel. Might be a lost cause if the campsite is too far from civilization. Been there, done that ;(. Digital signals do not travel as far as the old analog system did, unfortunately.
The dtv.gov site is useful too-
I never got my free government digital tuner and now I realize I should have. I was going to go camping and bring my old portable TV/weather radio/emergency light TV and realizes it still has the old analog tuner. It has both an RF connector and the two screw type connector as well as RCA. Where can I get a SMALL inexpensive and semi-portable digital TV converter? If the digital converter runs on 12VDC (or any common DC voltage) I can make an adapter that will power it from my camper, car, or my hand crank generator. I even have a gas generator. I just want it small enough to be portable and something not too pricy.