We didn't have a LOT of success in picking up satellite (Direct TV) while traveling in Alaska since the birds are so low in the sky that mountains don't have to be that close to block the signal. I have a total of about $50.00 invested in my entire RVing package which includes a mount (made from PVC pipe) and a used dish ($10.00 purchased from an installer) and the satellite signal finder from Radio Shack. The system works well and is easy to set up (takes about 10 minutes total). Not sure just how much better Dish network might be up there, for the same reasons. I actually have BOTH services (Direct on one home and Dish on another) and don't really have a preference for one over the other but it seems like Direct is easier to set up in the campground (guessing as I've never used DISH for that purpose). The have about the same services but different channels so you might do well to sign on to both web sites and go over the SPECIFIC programing you are interested in to be sure they have it. I've found more variety with Direct but if you want specific channels make sure the service you choose actually HAS that particular one.
Good luck / Skip