Out here, you can draw a square a hundred miles on a side, and find no-one living inside. The whole area had been evacuated when the nuclear pile under Cheyenne Mountain had grown to a critical size, and the meltdown irradiated the whole county. All the towns stood empty, cars had been left abandoned: nothing moved.
Apart from a motorcycle on I-70. The road is rutted, but she makes her way around the holes, weaving across the lanes towards Denver. She'd found out about Cheyenne, and had cut across fields to avoid the cordon; there was something under the mountain, and she was here to find out what.
She rolls up to the tunnel through the mountain, filled in by the collapse after the meltdown. The infill has been smoothed over, and a porthole window fitted at around waist height. She peers in, expecting to see only rock and stone, and sees —
Light. Spirals of light against a perfectly dark background, as if there were galaxies of stars through that porthole. A whole universe, underneath the mountain.
They say the universes in this ring start in the same place, and grow outward. They don't say where that place is.