Mount Baker-Snoqualmie National Forest, Washington

Survey Area WA762• Washington

The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low 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 Mount Baker-Snoqualmie National Forest, Washington. 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 Vitricryands-Rock outcrop association, 15 to 100 percent slopes	366K	Well drained	A	Very limited	Very limited
Typic Vitricryands-Andic Dystrocryepts, cold-Rock outcrop association, 15 to 100 percent slopes	316K	Well drained	B	Very limited	Very limited
Rock outcrop-Lithic Dystrocryepts-Glaciers association, 35 to 100 percent slopes	195K			Not rated	Not rated
Andic Haplocryods-Aquic Haplocryands association, 15 to 65 percent slopes	174K	Well drained	A	Very limited	Very limited
Typic Udivitrands-Aquandic Dystrudepts association, 0 to 35 percent slopes	124K	Well drained	A	Very limited	Very limited
Typic Udivitrands-Oxyaquic Haplorthods association, 0 to 35 percent slopes	89K	Well drained	A	Very limited	Very limited
Andic Dystrocryepts-Histic Cryaquepts-Andic Haplocryods complex association, 0 to 45 percent slopes	64K	Well drained	A	Very limited	Very limited
Typic Udivitrands-Rock outcrop association, 15 to 65 percent slopes	62K	Well drained	A	Very limited	Very limited
Vitrandic Humicryepts-Typic Vitricryands-Rock outcrop association, 35 to 100 percent slopes	48K	Well drained	A	Very limited	Very limited
Vitrandic Humicryepts, cold-Typic Vitricryands, cold-Rock outcrop association, 35 to 100 percent slopes	36K	Well drained	A	Very limited	Very limited
Andic Dystrocryepts, cold-Andic Haplocryods, cold-Rock outcrop association, 15 to 100 percent slopes	34K	Well drained	A	Very limited	Very limited
Andic Haplocryods, cold-Lithic Dystrocryepts-Histic Cryaquepts association, cold, 0 to 65 percent slopes	34K	Well drained	B	Very limited	Very limited
Rock outcrop-Glaciers association, 15 to 100 percent slopes	33K			Not rated	Not rated
Andic Dystrocryepts, cold-Oxyaquic Duricryands-Lithic Dystrocryepts association, 15 to 100 percent slopes	25K	Moderately well drained	B	Very limited	Very limited
Lithic Dystrocryepts-Rock outcrop-Typic Vitricryands association, 15 to 100 percent slopes	23K	Well drained	D	Very limited	Very limited
Vitrandic Dystrocryepts-Histic Cryaquepts association, 0 to 15 percent slopes	17K	Moderately well drained	C	Very limited	Very limited
Water	9K			Not rated	Not rated
Vitrandic Dystrudepts-Histic Humaquepts association, 0 to 15 percent slopes	7K	Moderately 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.

Andisols

Volcanic ash soils — light, porous, and fertile. Excellent drainage, but low density can complicate foundations.

Spodosols

Acidic forest soils with a leached layer. Common under conifers. Often have drainage issues from a compacted subsoil layer.

What This Means

Building & Foundations

About 85% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. A geotechnical assessment is recommended before building.

Septic Systems

About 85% 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.