Modern surface faulting, 4.8 km southeast of Picacho, Arizona, has created a scarf ranging from 0.2 to 0.6 m high and approximately 15 km long. The scarf, which has been steadily increasing in height since it began to form in 1961, occurs along the eastern margin of the Eloy-Picacho subsidence bowl where more than 2.9 m of land subsidence, caused by declines of groundwater levels, occurred from 1934 to 1977. Faulting is concluded to be related to groundwater withdrawal. First, the scarp is restricted to an area underlain by alluvium in which groundwater levels have declined. Second, faulting postdates the beginning of water level declines and associated land subsidence. Third, observed vertical displacements associated with faulting are compatible with results from a model of subsurface faulting in which rupture does not extend beneath the zone affected by stresses related to declines of water levels. The model is based on elastic dislocation theory. And fourth, analysis of levelings of bench marks unaffected by man-induced subsidence indicates minor regional crustal movements that do not appear to be compatible with the magnitude of fault offset.