I was just checking out Archuleta Mesa on Google Earth and it appears that they didnt really check out the mesa. They drove up in a snow cat what looks like a ridge in front of the actual Mesa. They show never even displayed an aerial map which I feel is crucial to understanding the whole story.

A final note. When I was studying the Dulce base story in the 90s the conclusion I came to was that the Military definitely had tunnels and underground facilities in the area but they stored Nuclear waste there and created the radical stories as a cover to keep nosy nells out.