OF-89-01 Field Studies and Modeling Analysis of the Roan Creek Landslide, Garfield County, Colorado


Study of the Roan Creek Landslide, Garfield County — a slump-earthflow complex caused by water infiltration and saturation of old landslide material. Includes: regional geology, climatology, hydrology, slope movements, field investigations, soil analysis, failure mode, and modeling analysis. 106 pages. 45 figures. 3 tables. 1 plate (1:24,000). Digital PDF download. OF-89-01D

The Roan Creek landslide is located in the Roan Creek drainage basin in Garfield County, Colorado on the north-facing slope of Kimball Mountain. It initially failed on 24 April 1985 and [at the time of publication] is 4000 feet long, has an elevation differential of 650 feet between head scarps and toe, and ranges in width from 500 to 1500 feet. At the time of initial failure, the rapid movement and large size of the landslide caused concern that Roan Creek might be dammed. However, the slide stopped fifty feet from Roan Creek at its narrowest approach.

Field studies were initiated to determine the cause and mode of failure of the Roan Creek landslide. Field mapping was conducted utilizing a large-scale topographic base map produced with the aid of photogrammetric techniques. The areal extent of the slide, all primary structural features, surface water and seeps, and lithologic zones were mapped.