We have been measuring tephra/soil erosion rates in the Smith, Bean, Clearwater, Upper Green River areas of the eastern part of the blast zone. Debris slides and debris flows have been inventoried based on field observations and interpretation of aerial photographs for the 1967 to 1984 period. Sheet and rill erosion was measured with arrays of erosion pins. Repeat photography of hillslope, channel, and revegetation changes has been done at a variety of locations. The intensity of measurements has been reduced through time, but all sites could be revisited and longer-term trends in erosion rates estimated.