Todd County, South Dakota

Survey Area SD121• South Dakota

The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low 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 Todd County, South Dakota. 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
Anselmo-Longpine fine sandy loams, 9 to 21 percent slopes	82K	Well drained	A	Somewhat limited	Very limited
Holt-Vetal fine sandy loams, 3 to 9 percent slopes	55K	Well drained	B	Not limited	Very limited
Valentine-Dunday complex, 3 to 9 percent slopes	52K	Excessively drained	A	Not limited	Very limited
Valentine fine sand, rolling and hilly, 9 to 60 percent slopes	40K	Excessively drained	A	Somewhat limited	Very limited
Anselmo fine sandy loam, 3 to 6 percent slopes	35K	Well drained	A	Not limited	Very limited
Keota-Epping silt loams, 9 to 21 percent slopes	35K	Well drained	C	Somewhat limited	Very limited
Longpine-Ronson fine sandy loams, 3 to 30 percent slopes	30K	Well drained	D	Very limited	Very limited
Valentine fine sand, 9 to 25 percent slopes	27K	Excessively drained	A	Somewhat limited	Very limited
Anselmo-Vetal fine sandy loams, 0 to 2 percent slopes	20K	Well drained	A	Not limited	Very limited
Kadoka-Epping silt loams, 3 to 9 percent slopes	20K	Well drained	C	Somewhat limited	Very limited
Anselmo fine sandy loam, 6 to 11 percent slopes	19K	Well drained	A	Somewhat limited	Very limited
Tuthill-Anselmo fine sandy loams, 3 to 9 percent slopes	18K	Well drained	B	Not limited	Somewhat limited
Valentine-Tassel complex, 5 to 30 percent slopes	18K	Excessively drained	A	Very limited	Very limited
Loup-Elsmere loamy fine sands	16K	Poorly drained	D	Very limited	Very limited
McKelvie-Peji complex, 40 to 80 percent slopes	15K	Excessively drained	A	Very limited	Very limited
Keota-Rock outcrop complex, 16 to 40 percent slopes	15K	Well drained	D	Very limited	Very limited
Holt fine sandy loam, 0 to 3 percent slopes	14K	Well drained	B	Somewhat limited	Very limited
Tuthill silt loam, 0 to 3 percent slopes	14K	Well drained	B	Not limited	Somewhat limited
Keota-Kadoka silt loams, 9 to 15 percent slopes	14K	Well drained	C	Somewhat limited	Very limited
Richfield-Tuthill silt loams, 2 to 9 percent slopes	13K	Well drained	B	Not 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.

Entisols

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

Inceptisols

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

What This Means

Building & Foundations

Most soils are generally favorable for residential construction. Standard foundations are usually viable, though site-specific evaluation is always recommended.

Septic Systems

About 94% 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

Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.