What soils affect foundations in east-central Oklahoma?

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

In short: East-central Oklahoma is wetter than the rest of central Oklahoma and is built largely on Pennsylvanian-age shale with sandstone ridges and broad river floodplains ¹²⁴. Many shale-derived soils hold a seasonal high water table within a few feet of the surface in winter and spring ¹²³, and floodplain clays such as Osage are Vertisols with smectitic clay ⁵. Wetting heave, crawl-space moisture and slope movement are common concerns.

Cities covered: Muskogee, McAlester, Okmulgee, Henryetta, Wagoner and eastern Shawnee.

What is the climate like?

USDA descriptions for the region's soils list mean annual precipitation of roughly 35 to 47 inches, with typical values near 39 to 41 inches, and mean annual temperatures of about 55 to 64 °F ¹²³. Statewide, rainfall climbs from about 17 inches in the far western Panhandle to about 56 inches in the far southeast ⁷, and this region sits on the wetter side of that gradient. Major Oklahoma floods frequently occur in spring and fall ⁶. See creeks and flood history.

What is the ground made of?

Shale clays

Much of the region is underlain by Pennsylvanian shales with thin sandstone and siltstone layers.

Eram: moderately deep soils from Pennsylvanian shale with thin sandstone, with bedrock at 20 to 40 inches and a seasonal high water table at 1 to 2 feet in winter and spring ¹.
Talihina: shallow, poorly drained clayey soils from soft Pennsylvanian shale, with soft bedrock at 10 to 20 inches, slow permeability and a perched water table within 0.5 to 2 feet from November to April. They occur on sloping to steep uplands of 5 to 30 percent ².
Okemah: very deep, somewhat poorly drained soils on high terraces and lower slopes, with a perched water table at 2 to 3 feet from December through April; type location in Okmulgee County ³.

A perched water table is a layer of saturated soil sitting above a tighter layer below.

Sandstone ridges

Hector soils are shallow, well drained soils formed from sandstone, with hard rock at 14 to 20 inches, on ridgetops and mountainsides with slopes of 2 to 60 percent ⁴. These are tied to Pennsylvanian sandstones.

Floodplain clays

Osage soils are very deep, poorly drained clays in thick alluvium on floodplains of major streams. USDA classifies them as Vertisols (Typic Epiaquerts) with smectitic clay and continuous slickensides from about 13 to 60 inches. They have very slow permeability and a seasonal high water table at 6 to 18 inches from November to May ⁵.

What are the main soils?

Series	Depth to rock	Drainage / water table	Notes
Eram	20–40 in	Moderately well; 1–2 ft in wet season	Shale with sandstone ¹
Talihina	10–20 in	Poorly; perched 0.5–2 ft Nov–Apr	Steep uplands ²
Okemah	Very deep	Somewhat poorly; perched 2–3 ft Dec–Apr	Some slickensides ³
Hector	14–20 in	Well drained	Sandstone ridges ⁴
Osage	Very deep	Poorly; 6–18 in Nov–May	Vertisol, smectitic ⁵

What foundation problems are common?

Perimeter wetting heave where shale clays stay wet through winter and spring.
Crawl space moisture and wood decay under homes on soils with shallow seasonal water.
Slope creep on steeper shale hillsides. The Oklahoma Geological Survey reports that most Oklahoma landslides occur in the eastern third of the state ⁶.
Settlement on soft floodplain clays.

The Oklahoma Geological Survey also lists the Arkoma Basin among the state's principal seismic areas, with typical small magnitudes of about 1.8 to 2.5 ⁶.

Statewide research put the depth of seasonal soil-moisture change at about 0.5 to 4 meters ⁷.

Common questions

Why are soils around Muskogee and Okmulgee often wet in spring?

Several common soils formed from Pennsylvanian shale have a seasonal high or perched water table within about 1 to 3 feet of the surface in winter and spring, according to USDA soil descriptions.

Which east-central Oklahoma soils swell the most?

Floodplain clays such as Osage are classified as Vertisols, with smectitic clay and continuous slickensides from about 13 to 60 inches deep.

How much rain falls in east-central Oklahoma?

USDA descriptions for the region's soils give mean annual precipitation of roughly 35 to 47 inches, with typical values around 39 to 41 inches.

Are landslides a concern in eastern Oklahoma?

The Oklahoma Geological Survey reports that most of the state's landslides occur in the eastern third, where the climate is wetter and the terrain steeper.

Sources

Official Series Description – ERAM Series USDA Natural Resources Conservation Service
Official Series Description – TALIHINA Series USDA Natural Resources Conservation Service
Official Series Description – OKEMAH Series USDA Natural Resources Conservation Service
Official Series Description – HECTOR Series USDA Natural Resources Conservation Service
Official Series Description – OSAGE Series USDA Natural Resources Conservation Service
Geologic Hazards in Oklahoma (GSA South-Central Section abstract) Oklahoma Geological Survey / Geological Society of America
Soil Matric Suction and Active Zone Depth in Oklahoma (PhD dissertation) Oklahoma State University

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