What are foundation conditions like in Altus, Oklahoma?
In short: Altus is clay country: about 58% of the city is mapped in soils rated high shrink-swell 1.
What does the soil survey show for Altus?
Altus covers about 18 square miles 2 and had 18,729 people in the 2020 Census 2.
| Measure | Share of the area |
|---|---|
| High shrink-swell soil (linear extensibility 6% or more) | 58% 1 |
| Moderate shrink-swell (3% to under 6%) | 29% 1 |
| Low shrink-swell (under 3%) | 2% 1 |
| Somewhat poorly or poorly drained | 12% 1 |
| Water table within 2 feet at some time of year | 0% 1 |
| Bedrock within 40 inches (soft or hard) | 0% 1 |
| Occasional or frequent flooding | 8% 1 |
Which soils matter most for houses in Altus?
- Tillman, about 30% of the area 1: Very deep, well drained, slowly permeable soils 3.
- Hollister, about 25% of the area 1: Very deep, well drained, very slowly permeable soils 4.
- Ozark, about 14% of the area 1: Very deep, moderately well drained, moderately slowly permeable soils that formed in loamy alluvium over residuum from redbed clays and claystones of Permian age 5.
- Rups, about 6% of the area 1: Very deep, somewhat poorly drained, moderately slowly permeable soils 6.
- Headrick, about 3% of the area 1: Very deep, somewhat poorly drained, moderately slowly permeable soils 7.
What does this mean for houses in Altus?
Clay that swells and shrinks. Where high shrink-swell soil sits under a house, wet spells lift the slab edges and drought drops them, and uneven watering does more harm than uniform change. See perimeter wetting heave, edge drop in drought and tree-root drying.
Which soils cover Altus?
| Soil | Share |
|---|---|
| Tillman | 30.4% 1 |
| Hollister | 24.7% 1 |
| Ozark | 14.3% 1 |
| Rups | 5.9% 1 |
| Headrick | 3.4% 1 |
| Treadway | 2.1% 1 |
| Tilvern | 1.7% 1 |
| Water | 1.3% 1 |
Looking for a foundation company near Altus?
Companies that serve Altus can appear on the company map in the Homeowner Hub. Paid listings there are marked Sponsored; the library and the AI guide don't rank or recommend any of them.
Buying or selling a house in Altus? Realtors who serve the area can be on the same map, also marked Sponsored, and for realtors covers the seller disclosure form, inspections and the sale timeline. Seeing cracks at home? Start with for homeowners.
How were these numbers measured?
We overlaid the city limits from the Census Bureau 2 on the USDA soil survey's map units 1 and added up the area of each soil. Where a map unit is a mix of soils, its area was split by the percentages the survey lists for its major soils, so shares leave out minor inclusions and do not add to 100%. Shrink-swell is rated by the linear extensibility of a soil's most expansive layer, the survey's measure of how much it changes length between wet and dry (6% or more is high). Water table, bedrock and flooding come from the survey's map-unit summaries: the shallowest water table in any month, the shallowest bedrock, and the most common flooding frequency. Bedrock here includes soft, weathered sandstone and shale that a pier can push through, so it is not the depth where piers stop. These are mapped averages, not a test of any one lot; fill, grading and the soil actually under a house can differ, which is why a site visit or soil boring still decides a repair.
Related
- Southwest red plains
- Lawton
- Elk City
- Clinton
- Anadarko
- Compare Oklahoma cities
- Shrink-swell and the active zone
Common questions
How much of Altus has expansive clay soil?
About 58% of Altus is mapped in soils rated high shrink-swell, 29% moderate and 2% low, measured inside the city limits from the USDA soil survey.
What is the most common soil in Altus?
Tillman, which covers about 30% of the city. USDA describes it as very deep, well drained, slowly permeable soils.
Is rock shallow in Altus?
Bedrock is within 40 inches of the surface under about 0% of the city, according to the USDA soil survey's map-unit data.
Does Altus have high groundwater or flooding?
The soil survey maps a water table within 2 feet of the surface at some time of year under about 0% of the city, and occasional or frequent flooding on about 8%.
Sources
- Soil Survey Geographic Database (SSURGO), queried through Soil Data Access, November 2026 USDA Natural Resources Conservation Service
- TIGERweb, 2020 Census: Incorporated Places and ZIP Code Tabulation Areas U.S. Census Bureau
- Official Soil Series Description: TILLMAN Series USDA Natural Resources Conservation Service
- Official Soil Series Description: HOLLISTER Series USDA Natural Resources Conservation Service
- Official Soil Series Description: OZARK Series USDA Natural Resources Conservation Service
- Official Soil Series Description: RUPS Series USDA Natural Resources Conservation Service
- Official Soil Series Description: HEADRICK Series USDA Natural Resources Conservation Service
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