Cheyenne Mountain Nuclear Bunker
This bunker, carved out of a mountain of granite, used to be command center for NORAD. The underground facilities were designed to withstand “all foreseeable weapons.” Reservoirs contain fresh and industrial water. Its blast doors can withstand a limited nuclear attack and the air intake can be filtered for chemical, biological, and radiological agents. In the event of a power disruption, backup batteries and six diesel generators would keep the bunker running.
Those who know their science fiction will recognize this site as where the Stargate was installed in the series Stargate SG-1. There is supposedly a broom closet located in the facility labeled “Stargate Command.” I chose this site as the location of the colony of refugees because it is could be well secured from attack, is prepared to function as a bunker, and is underground, which puts it beyond the ability of the Mechs to detect it.