The principal earthquake in the Walker Pass region on March 15, 1946, is located at , at a depth of 22 km., with origin time at 05:49:35.9 P.S.T. Epicenters of aftershocks scatter about this, with some indication of a NNE-SSW trend. The observed times fit a structure with layers 21.7 km., 9.7 km., and 10.7 km. thick. Velocities of the longitudinal and transverse waves agree with those previously determined by Gutenberg for southern California. The effect of the “root” of the Sierra Nevada is seen in the failure of Pn to record at Tinemaha, although it appears there on the seismograms of shocks east and west of the principal group.