It's quite amazing to see that people still living so remotely, in 2021. I wonder what most of them are accomplishing by using the mail. Do they have family they communicate with? Maybe children that have grownup and relocated?
Supai, Arizona [0] is only accessible by helicopter or an 8-mile hike from the nearest road.
https://fernweh.photo/2016/11/19/supai-arizona/
The helicopter "pad" and the hiking trailhead are themselves many miles from the nearest town. Supai is often claimed to be the most remote town in the 48 contiguous states.
Maybe that's why they all look so happy.