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

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

In short: Muskogee is a deep, moderately well drained soil on stream terraces in eastern Oklahoma and the lower Mississippi valley states. It has silt loam at the surface over a subsoil that becomes silty clay and then very firm clay below about 26 inches. Its slow permeability and clay lower subsoil make water management the central foundation issue.

What is Muskogee soil?

Muskogee is an official USDA soil series classified as "Fine-silty, mixed, active, thermic Aquic Paleudalfs" ¹. "Aquic" in a soil name signals periodic saturation and the reduced (oxygen-poor) conditions that come with it ³. The soil formed in silty material over clayey sediments on stream terraces ¹.

The series is mapped in Arkansas, Louisiana, Mississippi, eastern Oklahoma and western Tennessee, and possibly eastern Texas ¹. It was established in Muskogee County, Oklahoma, in 1913, but its type location is now in Franklin County, Arkansas ¹. Mean annual precipitation is about 45 inches ¹.

In Oklahoma, Muskogee soils fall within the East-Central (Arkoma) and Tulsa Metro regions, on Quaternary alluvium and terraces.

What is the typical soil profile?

Source for the table: ¹. Other properties from the official description ¹:

• Drainage: moderately well drained, slow to medium runoff ¹.
• Permeability: slow ¹.
• Lower subsoil: described as very firm and sticky ¹.
• Solum thickness: more than 60 inches; depth to bedrock is not stated ¹.
• Slopes: 1 to 15 percent (the setting section gives 1 to 12 percent); the typical profile is on a 2 percent slope ¹.

What does Muskogee soil mean for foundations?

Clay below a silty cap

The upper 14 inches of Muskogee are silt loam, while the subsoil becomes silty clay at about 26 inches and clay at about 46 inches ¹. Clayey soils swell as they gain water and shrink as they dry ⁴, so the clay lower subsoil is the part most likely to change volume.

The official description does not list a shrink-swell value. Soil surveys rate this as linear extensibility, from "low" (under 3 percent) to "very high" (9 percent or more) ⁵. The rated value for a mapped unit is listed in Web Soil Survey ².

Slow drainage

Slow permeability ¹ means water that soaks in near a house stays in the soil longer. The ASCE Geo-Institute guide identifies roof runoff, poor grading, irrigation and plumbing leaks as the moisture sources to control around shallow foundations ⁴. It suggests sloping soil away from the house at least 3 inches in 5 feet and discharging downspouts at least 3 feet out ⁴.

Related topics:

• Groundwater and perched water
• Surface drainage and grading
• Erosion, undermining and washout voids
• Fill consolidation settlement

Signs to watch

The ASCE guide lists stair-step cracks in brick, sticking doors and windows, sloping floors and concrete floor cracks about 1/16 inch or wider as indicators of foundation movement ⁴. See stair-step brick cracks and sloping floors.

How do you confirm the soil at a property?

Web Soil Survey shows mapped soil units and lets users generate custom soil reports ².

Related

• Soil series in the Tulsa metro
• Okemah soil
• Parsons soil
• Shrink-swell and the active zone
• Soil series index