A chronological sequence of plant macrofossil assemblages from twenty-five pack rat middens provides a record of desert scrub vegetation for most of the last 13,380 yr BP from a hyperarid portion of the lower Colorado River Valley.
the Late Wisconsin and early Holocene, the development of extensive desert vegetations was not delayed until the beginning of the middle Holocene. A regional vegetation mosaic of desert scrub and woodland existed at altitudes below 1000 m in the Mojave