[en] Published data for the Midway Valley area, suggest that since middle Miocene time, recognized regional faults have had average slip rates of less than 0.10 mm/yr. Slip rates in the last 8 Ma are estimated to be one-sixth of previous slip rates or less. The decrease in fault activity coincides with the waning of magmatism related to the Paintbrush tuff. Two important uncertainties are inherent in the slip rate estimates: the relative amount of strike-slip versus dip-slip displacement and the errors in precision of dating offset units. Reliable Quaternary slip rates and recurrence intervals are not yet available for the Midway Valley area. The apparent lack of fault scarps in alluvium, however, indicates that no important displacements have occurred in Holocene time, although several photolineaments have been identified. 18 refs., 4 figs., 2 tabs