Fremont County, Wyoming
USDA's soil survey flags shrink-swell clay on 4% of Fremont County's mapped land and a shallow water table under basements on 3%, both below the national shares of 15% and 29%. The soil survey maps 56% of the county's land area; these shares describe the mapped part.
83% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 90.2% a week earlier. FEMA's flood data list 7 flood losses here since 2016. 54% of homes were built before 1980, against 50% nationally; the median home dates from 1978.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Fremont County
| Expansive clay (limits slab homes) | 4.0% |
| High water table (limits basements) | 3.0% |
| Septic fields very limited | 54.3% |
| Clay swell (LEP, by area) | 3.4% |
| High-swell land (LEP 6%+) | 5.6% |
| Mapped soil | 3,322,995 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Bosler | 3% | n/a |
| Rock River | 3% | n/a |
| Persayo | 3% | n/a |
| Forelle | 3% | n/a |
| Carmody | 2% | n/a |
| Blazon | 2% | n/a |
How we count · survey areas WY613 (2025-09-04), WY647 (2025-09-04), WY677 (2025-09-04), WY713 (2025-09-04)
What the numbers mean here
Rain over the 12 months to August 2026: 13.13 in, 1.43 in below the 1991-2020 average year of 14.56 in.
USDA rates 54% of the land very limited for septic absorption fields.
With shrink-swell clay on 4% and a shallow water table on 3% of the land, the soil survey points to neither problem across most of Fremont County; conditions still vary lot by lot.
Drought
83% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 24 weeks, most recently on the September 15, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 83% |
| D2 severe or worse | 45.8% |
| D3 extreme or worse | 8.4% |
| D4 exceptional | 0% |
Flood losses since 2016
7 flood losses since 2016, $37,718 paid. The worst year was 2017, with 3.
| Year | Flood losses |
|---|---|
| 2016 | 3 |
| 2017 | 3 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 14.56 in |
| 12 months to August 2026 | 13.13 in (-1.43) |
| 2025 | 15.27 in (+0.71) |
| Wettest year since 1895 | 2017: 21.06 in |
| Driest year since 1895 | 1902: 8.32 in |
| Days with 1 inch or more, normal at RIVERTON (12 mi away) | 1 |
Homes
| Housing units | 17,469 |
| Median year built | 1978 |
| Built before 1980 | 54% |
| Built 2000 or later | 21% |
| Owner-occupied | 70% |
| Median value, owner-occupied | $268,800 |
| Single-family detached | 71% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Hot Springs County, WY | 47 mi | 17% | 3% |
| Sublette County, WY | 69 mi | 8% | 13% |
| Washakie County, WY | 74 mi | 5% | 2% |
| Natrona County, WY | 93 mi | 17% | 1% |
| Sweetwater County, WY | 97 mi | 3% | under 1% |
| Big Horn County, WY | 106 mi | 12% | 4% |
| Park County, WY | 111 mi | 12% | 9% |
| Teton County, WY | 114 mi | 7% | 6% |
Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status