Helen C. Gordon, in a letter which appeared in the 'SHAVER MYSTERY MAGAZINE', Vol. 1, No. 2, 1947, pp. 3234., described a strange experience she and her husband had with a massive subterranean cavern below southern New Mexico.
While driving near the Organ mountains southeast of Las Cruces, the two had spotted what seemed to be mine tailings high upon the forbidden-looking slopes. Being a bit curious and adventurous, they decided to spend some time and walk up the mountains and see if there were any mines as they suspected from the tailing piles. They finally reached the entrance to what they knew to be a mine, perhaps excavated sometime in the 1800's, and proceeded to explore it's interior. They made their way back into the dark interior, feeling their way along. They continued farther still until the entrance was a mere pinpoint of light, and suddenly they noticed that the right wall had disappeared into empty blackness. A natural or artificial 'wall' or partition blocked off most of the 'empty area', which spanned a considerable distance along the side of the horizontal mine. Just behind the 'wall' a narrow ledge ran along the top of what seemed to be a chasm.
The chasm was deeper than their lights could reach and appeared to be more of a natural result of some ancient geological activity rather than artificial. They looked around for some wood and combustible material and constructed a torch, which they then dropped down the pit. They watched fearfully and in awe as the torch light became smaller and smaller until it disappeared from view altogether.
After questioning some of the old timers in the area they learned that such chasms were encountered on rare occasions by miners, who referred to them as 'glory holes'. A glory hole is a natural shaft of such depth and expanse that it's bottom is difficult to plumb. The old miners apparently broke through to this 'glory hole' and left the partition of the rock there for safety purposes.