In the dry air of the cave, the biological processes that break down organic tissue were slowed or stopped entirely.

The result, over thousands of years, was not the preservation of a fresh-looking body — the tissues of the Spirit Cave individual were certainly desiccated and altered — but the retention of material that in a wetter environment would have been entirely consumed.

This desiccation preserved not just the body itself but the materials associated with it.

The tule mats, the rabbit-skin blanket, the moccasins — all of these organic materials survived in conditions where they would normally have decomposed within a few years.

They survived because the cave acted as a natural dehydrator, pulling moisture from everything within it and keeping the environment too dry for the microorganisms that would otherwise have consumed them.