The U.S. Geological Survey derives its leadership role in landslide hazard-related work from the Disaster Relief Act of 1974 (the Stafford Act).
Rainfall in any form will provide some drought relief. A good analogy might be how medicine and illness relate to each other.
The landslide that occurred during the 1980 eruption of Mount St.
See the list of  worldwide catastrophic landslides of the 20th century. 
At this time there is no collective landslide inventory for the entire United States.
Landslides can and do occur in every state and territory of the U.S.; however, the type, severity and frequency of landslide activity varies from place to place, depending on the terrain, geology, and climate.
Detailed locations of areas susceptible to debris flows are given on "Preliminary Soil-Slip Susceptibility Maps, Southwestern California" published as U.S.
Several kinds of maps are used to depict danger from landslides.
USGS landslide researchers have ongoing field projects in several areas of the U.S., including parts of the Pacific coastal ranges, Rocky Mountains, and the Appalachians.
It’s not possible to exactly predict the number of days or weeks that landslides remain a danger after heavy rain. Residents near mountain slopes, canyons, and landslide prone areas should stay alert even after heavy rain subsides.