This paper presents an approach to modeling the complete, time-dependent deformation in southern California. We make use of a variety of techniques to include the far-field plate motion, stress relaxation in the asthenosphere, aseismic fault slip within the elastic lithosphere, and the complex, three-dimensional nature of the faults within the southern California region. Among the conclusions of the work here are the following: (1) the data exhibit a marginal preference for a relatively thin lithosphere in southern California, (2) the most sensitive determinant for lithospheric thickness and viscosity of the asthenosphere is the rotation rate of the motion vectors toward or away from major faults, (3) major faults in southern California are slipping at depth, at or near their average Holocene rates, (4) a shallow, active decollement beneath the Transverse Ranges is apparently needed to realistically model the strain changes observed there, and (5) this modeling technique offers the best approach for understanding the complex deformation field in southern California.