Gallatin National Forest Area, Montana

Survey Area MT623• Montana

The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Gallatin National Forest Area, 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
Typic Cryochrepts-Rock outcrop-Rubbleland complex, cirque headwalls	120K		B	Not rated	Not rated
Typic Cryochrepts-Rock outcrop complex, steep	50K	Somewhat excessively drained	B	Very limited	Very limited
Rubble land, talus	40K		A	Not rated	Not rated
Typic Cryochrepts, glacial drift substratum	36K	Somewhat excessively drained	B	Somewhat limited	Somewhat limited
Rock outcrop-Typic Cryochrepts-Typic Cryoborolls complex, south aspect, steep	36K		B	Very limited	Very limited
Dystric Cryochrepts-Rock outcrop complex, granitic substratum	34K	Excessively drained	A	Very limited	Very limited
Rock outcrop-Typic Cryochrepts-Typic Cryoborolls complex, limestone substratum	31K		B	Very limited	Very limited
Mollic Cryoboralfs, mountain slopes, steep	27K	Well drained	C	Very limited	Very limited
Rock outcrop-Argic Cryoborolls-Mollic Cryoboralfs complex, steep	26K	Well drained	D	Very limited	Very limited
Mollic Cryoboralfs-Argic Cryoborolls complex, structurally controlled slopes, steep	26K	Well drained	C	Very limited	Very limited
Mollic Cryoboralfs-Argic Cryoborolls-Rock outcrop complex, structurally controlled slopes, steep	25K	Well drained	C	Very limited	Very limited
Aquic Cryoboralfs-Typic Cryoboralfs complex, landslides	25K	Somewhat poorly drained	C	Somewhat limited	Very limited
Typic Cryochrepts, obsidian sand substratum	25K	Well drained	A	Not limited	Very limited
Typic Cryochrepts, glacial drift substratum, steep	24K	Somewhat excessively drained	B	Very limited	Very limited
Typic Argiborolls-Mollic Eutroboralfs-Rock outcrop association, steep	23K	Well drained	B	Very limited	Very limited
Dystric Cryochrepts-Rock outcrop complex, steep	22K	Well drained	B	Very limited	Very limited
Mollic Eutroboralfs-Typic Argiborolls-Rock outcrop complex, steep	20K	Well drained	C	Very limited	Very limited
Dystric Cryochrepts, glaciated mountain ridges	20K	Well drained	A	Somewhat limited	Very limited
Typic Cryochrepts-Rock outcrop complex, volcanic substratum	20K	Somewhat excessively drained	B	Very limited	Very limited
Argic Cryoborolls-Typic Cryoborolls association, structurally controlled slopes	19K	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.

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.

Inceptisols

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

What This Means

Building & Foundations

About 59% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas. A geotechnical assessment is recommended before building.

Septic Systems

About 69% 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.