Landslide Susceptibility by ZIP Code
Data current as of August 2024 — recomputed by ZipCheckup from federal data each build.
In 1,213 of 3,214 U.S. counties (37.7%), the USGS slope-relief model maps at least half the land area as susceptible to landslides, and the national landslide inventory documents 593,961 landslides across that susceptible terrain in 52 states, as of August 2024. Susceptibility reflects where the ground is prone to sliding, not the odds that any single parcel will move.
The USGS maps at least half the land as landslide-susceptible in 1,213 of 3,214 U.S. counties, and its national inventory documents 593,961 landslides in that terrain, as of August 2024.
By state
We report two independent facts side by side and do not rank states. A larger count reflects the size of a state's inventory and its reporting activity, not a judgment about water safety.
| state | high susc county count | avg susc pct | documented landslides |
|---|---|---|---|
| AK | 15 | 59.8 | 23,869 |
| AL | 33 | 51.2 | 8 |
| AR | 29 | 38.7 | 76 |
| AZ | 6 | 50.5 | 7,910 |
| CA | 44 | 65 | 172,043 |
| CO | 37 | 51.3 | 30,286 |
| CT | 8 | 62.3 | 7 |
| DC | 1 | 51 | 1 |
| DE | 0 | 12.2 | 0 |
| FL | 0 | 5.2 | 1 |
| GA | 50 | 34.3 | 15 |
| HI | 4 | 63 | 448 |
| IA | 21 | 29.9 | 11 |
| ID | 28 | 57.9 | 204 |
| IL | 10 | 23.6 | 10 |
| IN | 20 | 29.1 | 4 |
| KS | 2 | 20.5 | 3 |
| KY | 95 | 72.9 | 19,291 |
| LA | 1 | 13.6 | 1 |
| MA | 7 | 51.1 | 9 |
| MD | 12 | 41.1 | 13 |
| ME | 5 | 45.9 | 2 |
| MI | 3 | 24.5 | 2 |
| MN | 5 | 18.5 | 14,241 |
| MO | 53 | 47.8 | 191 |
| MS | 35 | 42.7 | 7 |
| MT | 30 | 54.5 | 92 |
| NC | 43 | 44.5 | 11,392 |
| ND | 2 | 17 | 464 |
| NE | 20 | 34.8 | 2 |
| NH | 10 | 70.4 | 8 |
| NJ | 4 | 29.4 | 278 |
| NM | 9 | 34.7 | 2,580 |
| NV | 10 | 53.7 | 705 |
| NY | 31 | 47.9 | 91 |
| OH | 27 | 38.7 | 93 |
| OK | 6 | 28.3 | 169 |
| OR | 31 | 69.4 | 97,993 |
| PA | 57 | 64.9 | 4,153 |
| PR | 70 | 77 | 71,729 |
| RI | 1 | 37.4 | 0 |
| SC | 15 | 29.4 | 5 |
| SD | 5 | 21.1 | 7 |
| TN | 77 | 69.8 | 70 |
| TX | 6 | 15.4 | 6 |
| UT | 23 | 63.6 | 29,317 |
| VA | 91 | 61.4 | 40 |
| VT | 13 | 73.3 | 2,814 |
| WA | 30 | 66.8 | 69,802 |
| WI | 11 | 29.8 | 39 |
| WV | 54 | 94.2 | 385 |
| WY | 14 | 54.2 | 33,074 |
How we compute this
We use the USGS slope-relief threshold landslide susceptibility model (data release DOI 10.5066/P13KAGU3, 2024), which maps, across the United States and Puerto Rico, the land where slope and local relief make landslides likely. The release includes a per-county summary giving each county total area, the area mapped as susceptible, the resulting proportion, and the number of documented landslides from the USGS national landslide inventory that fall within that susceptible terrain.
For each county we record the share of land mapped as susceptible and the documented-landslide count, then sum across counties for national and per-state totals. A county is called high-susceptibility when at least half its land area is mapped as susceptible. Because the county is the unit, figures are summed across counties and never across ZIP codes, so no area is counted twice. Each county estimate maps to the ZIP codes within it, and figures recompute on every build.
County boundaries follow the 2010 census vintage used by the release. A small number of counties whose names do not resolve to a current FIPS code, mostly reorganized Alaska boroughs, are omitted rather than counted as zero. Susceptibility is a modeled measure of terrain proneness; it does not account for triggering events such as heavy rain or earthquakes, and it is not an engineering judgment about any specific site.
Frequently asked questions
How many U.S. counties are highly susceptible to landslides?
The USGS maps at least half the land area as landslide-susceptible in 1,213 of 3,214 counties it summarizes (37.7%), as of August 2024. This reflects where terrain is prone to sliding, based on slope and local relief, not a forecast that a landslide will occur. according to ZipCheckup's reading of federal data as of August 2024.
Does landslide susceptibility mean my property will have a landslide?
No. Susceptibility describes terrain that is prone to landslides because of its slope and relief; it is not a probability that any particular parcel will fail. Actual landslides depend on triggers such as intense rainfall, earthquakes, and human grading, and on site-specific conditions the county-level model does not capture. The USGS national inventory has documented 593,961 landslides within susceptible terrain nationwide as of August 2024.