The cave's environment preserved artifacts including fiber and skin garments, bags and mats.

The cave was formed by vertical faulting in a cliff face, which was periodically flooded by Lake Lahontan.

Heizer concluded that the remote location relative to the lake and marshes made Humboldt Cave a temporary refuge rather than a permanent residence.

[5] Apart from fur, feather, bone, wood and horn that had been damaged by insects and rodents, artifacts were recovered in near-perfect condition.

Pack rats jumbled much of the material, as was illustrated when, during excavation, a wool sweater was left in the cave.

[7] The most significant artifacts recovered during the excavation were usually found in one of 31 cache pits dug into the cave floor by the inhabitants.