Logan County, Oklahoma

Survey Area OK083• Oklahoma

The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). 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 Logan 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
Coyle-Ironmound complex, 3 to 5 percent slopes, eroded	28K	Well drained	C	Somewhat limited	Very limited
Stephenville-Darnell complex, 5 to 15 percent slopes	20K	Well drained	C	Somewhat limited	Very limited
Ironmound-Coyle complex, 5 to 15 percent slopes	19K	Well drained	D	Very limited	Very limited
Zaneis loam, 3 to 5 percent slopes, moderately eroded	18K	Well drained	B	Somewhat limited	Somewhat limited
Ashport silt loam, 0 to 1 percent slopes, frequently flooded	18K	Well drained	B	Very limited	Very limited
Stephenville-Darnell-Newalla complex, 3 to 8 percent slopes, eroded	18K	Well drained	C	Somewhat limited	Very limited
Grainola silty clay loam, 5 to 8 percent slopes, eroded	17K	Well drained	D	Very limited	Very limited
Darnell-Rock outcrop complex, 8 to 45 percent slopes	15K	Somewhat excessively drained	D	Very limited	Very limited
Masham-Ironmound complex, 5 to 15 percent slopes	14K	Well drained	D	Very limited	Very limited
Renfrow silty clay loam, 3 to 5 percent slopes, eroded	14K	Well drained	D	Very limited	Very limited
Stephenville-Darnell-Newalla complex, 3 to 8 percent slopes	11K	Well drained	D	Very limited	Very limited
Stephenville-Darnell complex, 1 to 5 percent slopes	11K	Well drained	C	Somewhat limited	Very limited
Grainola silty clay loam, 3 to 5 percent slopes	11K	Well drained	D	Somewhat limited	Very limited
Kirkland silty clay loam, 1 to 3 percent slopes	10K	Well drained	D	Very limited	Very limited
Stephenville-Darnell complex, 1 to 5 percent slopes, eroded	10K	Well drained	C	Somewhat limited	Very limited
Coyle loam, 3 to 5 percent slopes, eroded	9K	Well drained	C	Somewhat limited	Very limited
Piedmont silty clay loam, 3 to 5 percent slopes, eroded	9K	Well drained	D	Very limited	Very limited
Pulaski fine sandy loam, 0 to 1 percent slopes, frequently flooded	9K	Well drained	A	Very limited	Very limited
Zaneis loam, 1 to 3 percent slopes	8K	Well drained	B	Somewhat limited	Somewhat limited
Norge silt loam, 3 to 5 percent slopes, eroded	8K	Well drained	C	Somewhat 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.

Inceptisols

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

Entisols

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

What This Means

Building & Foundations

About 49% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.

Septic Systems

About 90% 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.