The evidence from his skeleton and from the cave does not resolve this question.

What can be said is that traversing more than a thousand feet of difficult cave passage at 10,700 feet elevation requires sustained physical effort that would be affected by altitude.

The combination of cramped posture (crawling, squeezing), physical exertion, cold temperature, and reduced oxygen would have been genuinely demanding.

A person who was already physiologically adapted to high altitude would handle these demands more effectively than someone making an unacclimated visit from lower elevation.

The physical robusticity of the man’s skeleton — the dense bone, the well-developed muscle attachment sites — is consistent with someone who had spent his life doing hard physical work.