The pattern of recent normal faulting in the eastern part of the Basin and Range province indicates that both planar, deep- cutting normal faults and more shallowly- dipping listric normal faults occur in the central overthrust belt of western Wyoming. The listric variety have previously been thought to not generate large earthquakes, however large fault scarps along two of these faults indicate this may be incorrect. This project will map the trace of these faults, trench across them and date offset deposits in order to assess the possibility that these faults have produced large earthquakes. The work will also use these data to help explain regional fault patterns in the eastern Basin and Range.