Across the road near the visitor center I got a few bars of T-Mobile- barely enough to send texts w photos.

We only got 3 channels: NBC and 2 Spanish channels. Apparently it depends on where your site is and how good of an antenna you have. As for T-Mobile, we had NO reception at the campground. From what we were told by the hosts, no cell provider works there. They have a landline just to answer calls about the campground. If you want to get online or make a call, you have to drive about 2 miles to the Sunset Crater National Monument parking lot, or about the same distance to HWY 89. The best reception we got was about 8 miles into the town of Flagstaff.

We had no cell reception inside the campground with either ATT or Verizon. However a very short drive outside the entrance did offer limited service on both. I am uncertain which one T-mobile uses. Hope this helps.