Real-time Data

The U.S. Geological Survey, in cooperation with the Eldorado National Forest, has installed monitoring instruments on the Cleveland Corral landslide that has the potential to affect Highway 50. Data from these instruments are used to detect changes in local conditions including

Sensors are sampled every second and data are transmitted from the landslide to a USGS computer every 15 minutes.

During January 1997, several large landslides closed Highway 50 between Placerville and South Lake Tahoe, California. The photograph below shows the catastrophic Mill Creek landslide that closed Highway 50 for 4 weeks. A number of other landslides are episodically active in this corridor during wet years.

The Highway 50 landslide monitoring system uses data acquisition systems and radio telemetry developed by the USGS Volcano Hazards Program to operate in remote, hazardous sites with limited power. In many landslides, infiltration of rainfall or rapid snowmelt increases groundwater pressures. These elevated pressures can, in turn, trigger landslide movement.

For More Information

Monitoring Status


Location Map


  • Mark Reid
    U.S. Geological Survey
    Landslide Hazards
    345 Middlefield Road MS 910
    Menlo Park, CA 94025