McClain County, Oklahoma

Survey Area OK087• Oklahoma

The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in McClain County, Oklahoma. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map Unit	Acres	Drainage	Hydro Group	Dwellings	Septic
Nash-Lucien complex, 5 to 12 percent slopes	63K	Well drained	D	Very limited	Very limited
Grant silt loam, 3 to 5 percent slopes, eroded	37K	Well drained	B	Somewhat limited	Somewhat limited
Stephenville fine sandy loam, 3 to 5 percent slopes, moderately eroded	25K	Well drained	C	Somewhat limited	Very limited
Nash-Lucien complex, 3 to 5 percent slopes	13K	Well drained	C	Somewhat limited	Very limited
Port silt loam, 0 to 1 percent slopes, occasionally flooded	13K	Well drained	B	Very limited	Very limited
Grant silt loam, 5 to 8 percent slopes, eroded	13K	Well drained	B	Not limited	Somewhat limited
Tamford-Grainola complex, 5 to 12 percent slopes	13K	Well drained	D	Very limited	Very limited
Grant-Port, frequently flooded, complex, 0 to 12 percent slopes	13K	Well drained	B	Somewhat limited	Somewhat limited
Stephenville-Gullied land complex, 1 to 8 percent slopes	12K	Well drained	C	Somewhat limited	Very limited
Gracemore loam, 0 to 1 percent slopes, frequently flooded	12K	Somewhat poorly drained	A	Very limited	Very limited
Renfrow silt loam, 3 to 5 percent slopes, eroded	12K	Well drained	D	Somewhat limited	Very limited
Stephenville fine sandy loam, 3 to 5 percent slopes	11K	Well drained	C	Somewhat limited	Very limited
Keokuk silt loam, 0 to 1 percent slopes, occasionally flooded	10K	Well drained	B	Very limited	Very limited
Water	8K		D	Not rated	Not rated
Kirkland silt loam, 1 to 3 percent slopes	7K	Well drained	D	Very limited	Very limited
Pulaski fine sandy loam, 0 to 1 percent slopes, occasionally flooded	7K	Well drained	A	Very limited	Very limited
Grant silt loam, 3 to 5 percent slopes	7K	Well drained	B	Somewhat limited	Somewhat limited
Pond Creek silt loam, 1 to 3 percent slopes	7K	Well drained	B	Somewhat limited	Somewhat limited
Gullied land-Grant complex, 3 to 8 percent slopes	7K	Well drained	C	Not limited	Very limited
Ashport, Port and Pulaski soils, 0 to 1 percent slopes, frequently flooded	7K	Well drained	B	Very limited	Very limited

Soil Orders in This Area

The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.

Mollisols

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

Alfisols

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

Vertisols

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

Entisols

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

What This Means

Building & Foundations

About 44% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.

Septic Systems

About 71% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.