Figure 4. -- Looking east across the downstream end of Lake San Cristobal at the delta of Slumgullion Creek (arrows; see fig. 5 for location). This delta is a fan that has formed by erosion of material on the surface of the Slumgullion earth flow and deposition of this material in Lake San Cristobal by Slumgullion Creek. Deposition probably began to occur soon after the original earth flow occurred about 700 yrs ago and is continuing at present.