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

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

In short: Collinsville is a shallow, sandy loam soil that sits on hard Pennsylvanian sandstone only 4 to 20 inches below the surface. It holds just 5 to 20 percent clay, drains quickly and sheds a lot of runoff. The series was first described in Tulsa County, and on these sites the closeness of rock and the handling of surface water matter more than clay swelling.

Where does Collinsville soil occur?

The USDA Natural Resources Conservation Service (NRCS) Official Series Description (OSD) maps Collinsville in Oklahoma, Kansas and Missouri, in Major Land Resource Areas 84A, 112, 118A and 118B ¹. It is an extensive series, established in Tulsa County in 1935, with its type location in Rogers County about 2 miles north and 1.5 miles east of Inola ¹.

Collinsville forms on interfluves (the ridges between drainages) and hillslopes, on slopes of 1 to 35 percent ¹. It weathered in place from Pennsylvanian sandstone ¹, one of the rock types that shape the Tulsa metro and the Northeast (Ozark Plateau and Grand Lake) region.

What are the key properties of Collinsville soil?

The word "Lithic" in the classification refers to this shallow contact with hard rock, which the OSD places at 10 to 50 cm (4 to 20 inches) ¹. Collinsville land is mainly native tallgrass range, with small areas of tame pasture ¹.

What do these properties mean for foundations?

Little swelling clay

Shrink-swell movement comes from clay soils that swell when wet and shrink when dry ⁴. With 5 to 20 percent clay and 30 to 75 percent sand ¹, Collinsville has far less clay than Oklahoma's expansive clays. NRCS rates shrink-swell by linear extensibility percent (LEP), with under 3 percent classed as low ³; the rated LEP for each map unit is in Web Soil Survey ².

Rock close to the surface

Hard sandstone lies only 4 to 20 inches below the surface of a Collinsville profile ¹. In Oklahoma steel push pier records, piers (steel pipes driven down to firm bearing) typically reached 8 to 16 feet, with a median of about 12 feet in Tulsa ⁵. On Collinsville sites the sandstone is much shallower than that, so a pier depth well under the regional median is consistent with the soil description. Whether shallow refusal is on continuous rock or on a loose ledge or boulder is a question for depth to rock from borings and bedrock in the Tulsa metro.

Runoff, erosion and fill

High runoff and a thin sandy soil over rock make concentrated water a concern ¹. Uneven moisture and leaks are common triggers for localized movement ⁴. Where fill was placed to level a lot, it is not part of the native profile the OSD describes ¹; see erosion, undermining and washout voids and fill consolidation settlement.

How do you check a specific lot?

• Look up the map unit and depth-to-bedrock rating in Web Soil Survey ².
• Route downspouts away from the foundation and grade soil to drain away from the house ⁴.
• Track cracks over time and check drainage around the house yearly ⁴.

Related

• Soil Series - Tulsa Metro
• Bedrock - Tulsa Metro
• Steel Push Piers
• Coweta soil
• Soil Series Index