Landslides affect all 50 states and U.S. territories, where they cause 25 to 50 deaths and more than $1 billion in damages each year. Geoscientists study and monitor landslides to identify at-risk areas, prepare populations, and improve our understanding of why, when, and where landslides happen.


2014 Oso, Washington Landslide. Image Credit: USGS/Photo by Mark Reid

Landslides are masses of earth, rock, or debris that move down slopes. Landslides are triggered by one event, but many causes can weaken slopes over time and make them more likely to fail when there is a triggering event. These causes can be both natural and artificial. Landslides often occur in areas with oversteepened slopes, weak soils/bedrock, or de-vegetated slopes (whether by human deforestation or natural events such as wildfires).[1] Some of the most damaging landslides are triggered by water, typically from intense short-term rainfall or long-term saturation of the slope. Both natural and human activities (such as irrigation or seepage) can saturate hillsides. Earthquakes and volcanic eruptions also cause damaging landslides.[1]   Read more

Frequently Asked Questions

Latest News

March 22, 2017 Senators Maria Cantwell (D-WA) and Lisa Murkowski (R-AK) introduced the bipartisan National Landslide Preparation Act (S.698) on March 22. The bill directs the U.S. Geological Survey (USGS) to establish a National Landslide Hazards Reduction Program. This program would identify and...
Mount St. Helens
July 12, 2016 The Hazards Caucus Alliance, a network of organizations that promotes nationwide natural disaster resilience, held a briefing to highlight the role that science plays in protecting communities that are vulnerable to lahars. Introductory remarks from Senator Lisa Murkowski (R-AK) were...
Capitol at night
March 17, 2016 Congresswoman Suzan DelBene (D-WA) has introduced new legislation  in an effort to decrease losses and damages as a result of landslides.  The new bill, the National Landslide Loss Reduction Act (H.R. 4776) would create the National Landslide Hazards Reduction Program and two...

Case Studies & Factsheets


More than just volcanic eruptions Volcanic eruptions are a serious hazard. But at many stratovolcanoes in Washington, Oregon, Northern California, and Alaska, landslides and debris flows can be just as dangerous. Some of these - especially volcanic mudflows (lahars) - are directly triggered by...

Fig. 1. A 1995 landslide in Overland Park, Kansas, destroyed two homes and damaged four lots. Credit: Kansas Geological Survey

Defining the Problem Damaging landslides occur even in vertically challenged states like Kansas (Fig. 1). It is important to be able to delineate landslide hazard areas in order to develop appropriate land-use plans. In Leavenworth County, Kansas, geologic maps combined with maps of landslide...

Fig.1. Home in Oakland, CA, destroyed by landslides in 1958. Source: J. Coe, USGS

Defining the Problem The geologic history of the Oakland, California, area has produced steep hillsides and unstable rock and soil that generate damaging landslides during severe storms and wet winters (Fig. 1 and 2). During the 1997-98 rainy-season, the two-county area surrounding Oakland...

Fig. 1. Homeowners and emergency managers are still coping with debris flows and the aftermath of the 2002 Missionary Ridge wildfire near Durango, CO. Credit: P. Winkworth

Defining the Problem Wildfires, such as the Missionary Ridge fire that burned for more than a month in 2002 near Durango, Colorado (Fig. 1), and their aftermath can cause subsequent property and environmental damage. Many areas denuded by the fire are now susceptible to rapid erosion during...

Fig. 3. U.S. Highway 85 crossing the Little Missouri River. Seventy-five percent of the rocks in this photograph, all of those in the foreground and the rocks along the north valley wall in the background have slid and are out of place. Credit: E. Murphy

Defining the Problem U.S Highway 85 and ND Highway 22, along with numerous county roads, buildings, pipelines, and power lines, have been constructed over existing landslides in the Little Missouri Badlands of western North Dakota. Since 1980, the repair and rerouting of damaged sections of...

Research Database Publications

Cover of fs_landslide_hazards; Source: Washington Division of Geology and Earth Resources
2015, Washington Division of Geology and Earth Resources (WA DGER)
Washington is one of the most landslide-prone states in the country, with hundreds to thousands of events each year. The direct cost of landslide damage includes the repair of roads and property. Indirect costs, such as loss of property value and tax revenue, and environmental effects, such as the...
Cover of fs_landslide_processes; Source: Washington Division of Geology and Earth Resources
2015, Washington Division of Geology and Earth Resources (WA DGER)
A landslide generally refers to the downhill movement of rock, soil, or debris. The term landslide can also refer to the deposit that is created by a landslide event. This fact sheet is meant to provide general information only; real landslides have many variables.
Cover of ofr20161044; Image credit: U.S. Geological Survey
2016, U.S. Geological Survey (USGS)
The U.S. Geological Survey (USGS) Earthquake Hazards and Landslide Hazards Programs are developing plans to add quantitative hazard assessments of earthquake-triggered landsliding and liquefaction to existing real-time earthquake products (ShakeMap, ShakeCast, PAGER) using open and readily...
Fig. 1. A 1995 landslide in Overland Park, Kansas, destroyed two homes and damaged four lots. Credit: Kansas Geological Survey
2004, American Geosciences Institute (AGI)
Landslide hazard maps based on geologic maps are a tool for local government officials, planners, developers, engineers, insurance companies, lending institutions, and landowners to assess the risk and take appropriate actions.
Cover of factsheet; Image credit: Hazards Caucus Alliance
2014, Hazards Caucus Alliance (HCA)
Landslides are a destructive geologic hazard with localized but significant impacts. In an average year in the United States, landslides cause the deaths of 25 to 50 people and economic losses of at least $2 billion. State and local entities take significant responsibility for landslide mitigation...
Cover of B-55; Source: Colorado Geological Survey
2015, Colorado Geological Survey (CGS)
On May 25th, 2014 the longest landslide in Colorado’s historical record occurred in west-central Colorado, 6 mi southeast of the small town of Collbran in Mesa County. Three local men perished during the catastrophic event. The landslide was 2.8 miles long, covered almost a square mile of the West...
Cover of 87-3; Source: Maine Geological Survey
1987, Maine Geological Survey (MGS)
A survey conducted by the Maine Geological Survey has provided information on recent and historical slides throughout the State of Maine (see Plate 1, Landslides in Maine). The landslide inventory questionnaire (Figure 1) was distributed to nearly 1,000 geologists, soil scientists, site evaluators...
Cover of SP33; Source: Colorado Geological Survey
1989, Colorado Geological Survey (CGS)
A guide for state and local government on reducing loss due to landslides. Includes types, causes, and losses of landslides; benefits of mitigation, hazard identification, assessment and mapping; use of communication; loss-reduction techniques; plan preparation and review; overcoming anticipated...
Fig.1. Home in Oakland, CA, destroyed by landslides in 1958. Source: J. Coe, USGS
2004, American Geosciences Institute (AGI)
In California, detailed modern geologic maps are fundamental for evaluating how susceptible an area is to earthquake-induced landslides.
Cover of RI_34_12; Source: Kentucky Geological Survey
2015, Kentucky Geological Survey (KGS)
Kentucky Transportation Cabinet maintenance cost data for landslides and rockfalls were associated with geology along Kentucky roadways in a three-phase study. Work-order costs collected over 7 yr were divided into 1-mi segments, and the segment midpoints were assigned to geologic units in order to...