[FreedomFarmer]

Makes sense to me. Cool stable temperature, out of the sun, and out of sight. Water source and animal fodder would have to be available locally, but everything else could be packed in.
I believe I have read that Australian gem miners live underground in the desert.

[blam]

There's a fire station in Creede, Colorado that is built in an old horozontal mine shaft. They said the year round temperature in there was 54 degrees, +- 1 degree.