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Where do landslides occur?

Landslides occur in every state and U.S. territory including the Appalachian Mountains, the Rocky Mountains, the Pacific Coastal Ranges, and some parts of Alaska and Hawaii. Any area composed of very weak or fractured materials resting on a steep slope can and will likely experience landslides.

Debris flow in channel near Butte Camp, Mount St. Helens, Washingto...
Debris flow in channel near Butte Camp, Mount St. Helens, Washington.


Where do landslides occur?

  • Landslides typically start on slopes, most commonly on steeper slopes
  • Landslides usually occur in areas where they've happened before 
  • Landslides typically occur on slopes with fractured materials (e.g., rock, debris, ice), deep soils, or thin soils over bedrock. 
  • Slopes with mature, healthy, native vegetation tend to have strong root systems that help hold soil in place, which may reduce the landslide hazard
  • Some landslides can travel hundreds to thousands of feet in stream channels, far from where the landslide started




Landslide susceptibility maps across the U.S.

Map of Puerto Rico landslide susceptibility with grey areas near the coast and colored areas in mountainous inland regions
The USGS Puerto Rico Landslide Susceptibility Map provides an interactive tool to assess landslide risk in Puerto Rico from low susceptibility to extremely high.
Video Transcript
Woodard (2023) Mapping landslide susceptibility over diverse regions with limited data, USGS Landslide Hazards Seminar, 10 May 2023
Video Transcript
Delong (2022) Landslide susceptibility in Minnesota: Insight from landslide inventory mapping and lidar change detection. USGS Landslide Hazards Seminar, 14 September 2022.
Although the physical cause of many landslides cannot be removed, geologic investigations, quality engineering practices, and effective enforcement of land-use management regulations can reduce landslide hazards. USGS scientists continue to produce landslide susceptibility maps for many areas in the United States. In every state, USGS scientists monitor streamflow, noting changes in sediment load carried by rivers and streams that may result from landslides. Hydrologists with expertise in debris and mudflows are studying these hazards in volcanic regions.
Center map shows landslide locations. Hills slope from sides down to center of figure with descriptive labels and arrows.
The University of Puerto Rico Mayagüez, the Natural Hazards Center at the University of Colorado Boulder, and the USGS Landslide Hazards Program collaborated to create educational materials for residents of Puerto Rico to learn about how to prepare for, mitigate, respond to, and recover from landslides. Pages from “Landslide Guide for Residents of Puerto Rico “ are shown in this figure. The project’s products describe landslide risk in a format accessible to a wide variety of audiences, from children to emergency managers. All the educational materials, including the “Landslide Guide for Residents of Puerto Rico,” can be accessed via the Landslide Hazard Mitigation Project website: