Fault-plane solutions were obtained for 80 microearthquakes in a 900-km2 area centered on the Busch fault during a 1-year period preceding the Thanksgiving Day, 1974, Hollister, Calif., earthquake. Strike-slip motion occurred in 64 of these quakes, mainly at active points on the Sargent, Castro, Busch, and Calaveras faults. Eleven of the solutions are thrust type, and five are normal. No large rotation (greater than 45¿) of the compressional axes was observed before the earthquake, but changes of about 20¿ or less would be possible.