I have AT&T regular cell service. During my recent week in the Whitney-area mountains, I was startled by an incoming call while my cell was in my pocket heading up the first steep part of the MR (in the woods) somewhat before the first water crossing. Seeing 2-3 bars, I was also able to make an outgoing call from that spot as well.

Ditto for somewhere on the lower part of the MT during the same week.

I was also able to make several calls from the top of Kearsarge Pass out of Onion Valley, with almost full bars. Of course these experiences were off and on and couldn't be relied on 100% of the time.

CaT

If future generations are to remember us with gratitude rather than contempt, we must leave them more than the miracle of technology. We must leave them a glimpse of the world as it was in the beginning, not just after we got through with it.
- Lyndon Johnson, on signing the Wilderness Act into law (1964)