Sites occur primarily between ca.
36 N and 38 30'N latitudes, and from ca. 1000 m to over 3000 m elevation on both sides of the Sierran crest, although more sites have been analyzed on the west side of the crest than the east side. Significant gaps in our knowledge occur for much of the east side of the crest, for both sides of the range above modern treeline, and for time periods older than the latest Pleistocene.