Analysis of geodolite observations in the coast ranges of northern California indicates that relative plate motion is spread over a wide zone. Little or no deformation occurs to the southwest of the San Andreas Fault itself. To the northeast of the San Andreas fault, a region transected by the parallel Rodgers creek and Maacama faults, 25¿6 mm/yr of right-lateral slip is distributed over about 60 km. There is a peak shear strain of 0.6¿0.1 μrad/yr near the San Andreas fault. Elsewhere in the deforming zone, shear strains rates are 0.3¿0.04 μrad/yr. At the northeastern boundary of the study area the strain rate is less than 0.2 μrad/yr. Except for the high strain rate near the San Andreas fault, there is no evidence of any localization of deformation to the surface traces of the faults, nor is there any evidence of creep or aseismic slip on any of the faults in the area. The data indicate that the relative motion between the Pacific and North American plate occurs primarily to the northeast of the San Andreas fault. The observations are inconsistent with models that include slip at depth on only the San Andreas fault. The data can be fit equally well by models with slip at depth on all three of the major faults or with motion distributed across the entire zone from the San Andreas fault to the Napa Valley fault. Preliminary analysis of observations to the Farallon Islans, about 40 km southwest of the San Andreas fault, suggests that little or no additional relative motion is accommodated on that side of the San Andreas fault. In particular, it is unlikely that the 20-mm/yr difference between the plate motion rate (about 55 mm/yr) and the San Andreas fault system rate (about 35 mm/yr) can be explained by deformation between the San Andreas fault and the Farallon Islands.