Landslide Photo Collections

An active rockslide in Merced River Canyon was first noticed on April 29, 2006 when a few rocks rolled onto Highway 140 between mileposts 103 and 104, compromising traffic on this highway and signaling the onset of renewed activity of the Ferguson rockslide. State highway 140 is one of the main entrances to Yosemite National Park and is the primary road for large commercial trucks access into the park from the west. Continued rockslide activity during 2006 built a large talus cone that covered the highway and encroached into the Merced River below it. As of 2008, the rockslide is still being monitored. Observations by the US Forest Service (USFS), the California Department of Transportation (CALTRANS), and the U.S. Geological Survey (USGS) confirm that the rockslide remained active through 2006 and represents a potential threat to traffic along the rerouted highway as well as to recreational users of the Merced River in the runout path below the rockslide. Delineation of the hazards posed by the Ferguson rockslide is a necessary prerequisite to mitigating them. For more information, please see USGS Report online: http://pubs.usgs.gov/of/2007/1275/