Oklahoma Soil Surveys

77 survey areas

Oklahoma has 77 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter, making up roughly 43% of surveyed soils. Alfisols — moderately leached forest soils with a clay-enriched subsoil account for another 25%.

In terms of drainage, 71% of Oklahoma soils are classified as well drained. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.

Soil Types

Mollisols

43% of surveyed soils

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

Alfisols

25% of surveyed soils

Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.

Entisols

12% of surveyed soils

Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

Inceptisols

11% of surveyed soils

Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.

Vertisols

4% of surveyed soils

High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.

Ultisols

3% of surveyed soils

Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.

Survey Areas

Oklahoma Soil Surveys

Soil Types

Survey Areas

Look Up a Specific Address