Landslide Photo Collections

On the evening of July 21, 2007, a slow-moving thunderstorm triggered about 45 debris flows on steep mountainsides near the community of Alpine, Colorado. Most of the debris flows were initiated by surface-water runoff that eroded and entrained loose sediment in previously existing channels. For more information and additional photos, please see a U.S. Geological Survey report online: http://pubs.usgs.gov/of/2007/1237/pdf/OF2007-1237.pdf