The major products of wind action in the Mojave - dunes, sand sheets, deflation basins, and deeply abraded rock surfaces - are interpreted to have been formed during a past arid interval followed by an extended time of relative eolian quiescence. Evidence for this is found in: (1) dissection of eolian sand deposits by gullies and stream channels; (2) occurrence of stabilized and modified dune surfaces; (3) accumulations of coarse detrital material mantling depositional slopes on eolian sand; (4) weathering of sand-blasted rock surfaces; and (5) gaps between eolian effects and sources of sand which must have produced them. These indicators occur in different combinations at different places. On the basis of comparison with established chronology in other places, the time of maximum wind action is assigned provisionally to the Altithermal, roughly 7500 to 4000 years ago. Present-day wind action is believed to represent a relatively recent reactivation. These findings have significant implications for playa morphology and stratrigraphy.