Carter County, Montana

Survey Area MT011• Montana

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 Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Carter County, Montana. 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
Eapa loam, 2 to 8 percent slopes	92K	Well drained	B	Somewhat limited	Somewhat limited
Neldore-Bascovy clays, 4 to 15 percent slopes	76K	Well drained	D	Very limited	Very limited
Gerdrum-Absher complex, 2 to 8 percent slopes	61K	Well drained	D	Very limited	Not limited
Rock outcrop-Moyerson complex, 15 to 50 percent slopes	50K		D	Not rated	Not rated
Neldore clay, 4 to 15 percent slopes	46K	Well drained	D	Very limited	Very limited
Orinoco-Yawdim silty clay loams, 4 to 15 percent slopes	46K	Well drained	D	Somewhat limited	Very limited
Marvan silty clay, warm, 2 to 8 percent slopes	46K	Well drained	D	Very limited	Not limited
Archin-Absher complex, 2 to 8 percent slopes	45K	Well drained	D	Somewhat limited	Not limited
Marvan silty clay, warm, 0 to 2 percent slopes	43K	Well drained	D	Very limited	Not limited
Archin loam, 2 to 8 percent slopes	43K	Well drained	C	Not limited	Not limited
Gerdrum clay loam, 2 to 8 percent slopes	42K	Well drained	D	Very limited	Not limited
Creed-Gerdrum complex, 2 to 8 percent slopes	41K	Well drained	C	Very limited	Not limited
Moyerson silty clay loam, 4 to 15 percent slopes	40K	Well drained	D	Very limited	Very limited
Moyerson-Orinoco silty clay loams, 4 to 15 percent slopes	37K	Well drained	D	Very limited	Very limited
Absher-Gerdrum complex, 0 to 4 percent slopes	35K	Moderately well drained	D	Very limited	Somewhat limited
Vanda-Marvan complex, 0 to 2 percent slopes	30K	Well drained	D	Very limited	Very limited
Delpoint-Cabbart complex, 8 to 15 percent slopes	30K	Well drained	C	Somewhat limited	Very limited
Havre loam, 0 to 2 percent slopes	27K	Well drained	B	Very limited	Somewhat limited
Yamacall-Cabbart loams, 15 to 35 percent slopes	26K	Well drained	B	Very limited	Very limited
Bickerdyke clay, 0 to 2 percent slopes	26K	Well drained	C	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.

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.

Alfisols

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

Mollisols

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

Vertisols

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

What This Means

Building & Foundations

About 65% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 40% of soils have significant septic limitations, while others are more suitable. A perc test is essential — conditions vary across the area.

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.