What is Hollister soil and how does it affect Oklahoma foundations?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: Hollister is a clay Vertisol of the Red Plains of southwest Oklahoma and north Texas, formed in calcareous Pleistocene clays over Permian sediments. Its layers hold 35 to 55 percent smectitic clay, and cracks extend deeper than 30 inches and stay open 150 or more days in most years. It belongs to the soil order defined by shrink-swell behavior, so seasonal foundation movement is the key issue.

Where does Hollister soil occur?

The USDA Natural Resources Conservation Service (NRCS) Official Series Description (OSD) places Hollister in Texas and Oklahoma, in Major Land Resource Areas 78B and 78C, the Central Rolling Red Plains ¹. It is described as extensive ¹. The type location is in Hardeman County, Texas, near Chillicothe ¹.

Hollister forms on paleoterraces (old, high terraces) on broad plains, on slopes of 0 to 3 percent ¹. Its parent material is Pleistocene calcareous alluvial clay deposited over Permian sediments ¹. In Oklahoma this is the Southwest (Lawton and Red Plains) region; see Quaternary alluvium and terraces and Western Permian red beds.

What are its key properties?

"Calcareous" means the material contains calcium carbonate (lime). Hollister is mainly cropland for wheat, cotton and grain sorghum ¹.

Why does Hollister soil move?

A true shrink-swell soil

Vertisols are clay-rich soils with at least 30 percent clay to 50 cm; they shrink as they dry and swell as they rewet, opening deep, wide cracks and forming slickensides, the polished, grooved surfaces found in these clays ⁵. That shrink-swell action causes serious engineering problems, including damage to structures ⁵. In Hollister, slickensides begin 8 to 20 inches down and cracks reach below 30 inches ¹.

NRCS rates shrink-swell by linear extensibility percent (LEP): 6 to 9 percent is high and 9 percent or more very high ³. The LEP for each Hollister map unit is listed in Web Soil Survey ².

What it does to a house

Clay soils heave when they gain moisture and settle when they dry, and uneven moisture does more damage than uniform moisture ⁴. Movement patterns described elsewhere on this site:

• Perimeter drying settlement
• Perimeter wetting heave
• Center heave under slabs
• Tree-root desiccation settlement

Signs include stair-step brick cracks, sticking doors and windows, sloping floors and slab cracks 1/16 inch or wider ⁴; see cracks that open and close seasonally.

A dry climate

Hollister's area averages about 25 inches of rain a year ¹, and its cracks stay open for 150 or more days in most years ¹. The ASCE guide describes watering evenly around a foundation and adding more water on the drier south and west sides during drought, to keep soil moisture uniform ⁴.

What are the practical points for a Hollister lot?

• Look up the map unit and LEP in Web Soil Survey ².
• Keep soil moisture uniform around and under the foundation ⁴.
• Plant trees farther from the house than their mature height ⁴.
• Repair leaks quickly; leaks cause localized movement ⁴.

Related

• Foard soil
• Durant soil
• Shrink-Swell and Active Zone
• Drought and Wet Cycles
• Soil Series Index