Figure 1.-- Location of GPS stations on the Slumgullion landslide and bench mark velocities calculated during a 4-day measurement period. The coordinates of station SEI1 are held fixed relative to the rest of the network. Stations SEI1 and T03A are thought to be located on the inactive portion of the slide. Velocity measurement errors (table 1) suggest the motion of station T03A may be within the measurement noise. Dotted lines indicate the location of major structural elements on the landslide.