Treasure County, Montana

Survey Area MT103• 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 Entisols — young soils with little profile development, often on floodplains or steep slopes. 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 Treasure 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
Midway-Bainville complex	79K	Well drained	D	Very limited	Very limited
Midway clay loam, 15 to 35 percent slopes	41K	Well drained	D	Very limited	Very limited
Midway-Shale outcrop complex, 4 to 35 percent slopes	29K	Well drained	D	Very limited	Very limited
Midway-Nihill gravelly loam	24K	Well drained	D	Very limited	Very limited
Pierre-Lismas clays, saline-Alkali	24K	Well drained	D	Very limited	Very limited
Hoven and McKenzie soils	20K	Well drained	D	Very limited	Very limited
McRae-Bainville loams, 8 to 20 percent slopes	20K	Well drained	B	Somewhat limited	Somewhat limited
Bainville loam, 15 to 35 percent slopes	18K	Well drained	D	Very limited	Very limited
Bainville-Midway complex, 15 to 35 percent slopes	16K	Well drained	D	Very limited	Very limited
Bainville-Shale outcrop complex	16K	Well drained	D	Very limited	Very limited
Havre loam	13K	Well drained	B	Very limited	Somewhat limited
Pierre-Lismas clays	12K	Well drained	D	Very limited	Very limited
Marias clays, fans, saline-alkali	12K	Well drained	D	Very limited	Very limited
Marias-Hoven clays, saline	12K	Well drained	D	Very limited	Very limited
Lismas-Pierre clays, saline-Alkali	12K	Well drained	D	Very limited	Very limited
Lismas-Midway complex	11K	Well drained	D	Very limited	Very limited
Bainville loam, 8 to 15 percent slopes	11K	Well drained	C	Somewhat limited	Very limited
Blacksheep-Twilight fine sandy loams, 15 to 40 percent slopes	10K	Well drained	D	Very limited	Very limited
Cushman loam, 4 to 8 percent slopes	9K	Well drained	C	Somewhat limited	Very limited
Fort Collins loam, 4 to 8 percent slopes	9K	Well drained	B	Not limited	Somewhat 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.

Entisols

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

Aridisols

Dry-climate soils with low organic matter. Often have caliche layers that make excavation difficult. Low shrink-swell is good for foundations.

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 87% 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 89% 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.