Why does mom get cell phone service in the mountains and I don't?

She has the LG 6G and i have the iPhone 7 plus. We both have Verizon and we're on the same plan. But we will be in the mountains and she get's service and I don't. Why is that?

Not sure.

Maybe the different models of phones use different ranges of frequencies,
some of which are not available everywhere.

You see…
Different cell sites, which are typically spaced a few hundred yards to a few miles apart,
are not necessarily all the same age and may have different capabilities.

You would have to do a lot of question-asking
to people you probably can't easily reach (at Verizon)
to get a full answer.

Since your on the same network you should both be getting a good signal, did you try doing a software update? Apple has their own antenna technology, this time that tech might be working against you. Also try removing your sim card and adding back on.