North Cascades National Park Complex, Washington

Survey Area WA774• 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 Andisols — soils formed in volcanic ash, very light and porous. 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 North Cascades National Park Complex, 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
Rock outcrop-Glaciers-Harlequin complex, 25 to 100 percent slopes	144K			Very limited	Very limited
Doubtful-Treen-Rock outcrop complex, 35 to 100 percent slopes	73K	Well drained	D	Very limited	Very limited
Doubtful-Triumph-Perfect complex, 35 to 100 percent slopes	68K	Well drained	B	Very limited	Very limited
Mox-Doubtful-Perfect complex, 35 to 100 percent slopes	55K	Well drained	A	Very limited	Very limited
Stetattle-Doubtful-Arriva complex, 15 to 100 percent slopes	52K	Well drained	B	Very limited	Very limited
Spickard-Tepeh-Maggib complex, 15 to 100 percent slopes	52K	Well drained	A	Very limited	Very limited
Thorton-Ragged-Benzarino complex, 35 to 100 percent slopes	37K	Well drained	A	Very limited	Very limited
Stetattle-Forbidden-Triumph complex, 15 to 65 percent slopes	22K	Well drained	A	Very limited	Very limited
Despair-Goode-Rock outcrop complex, 35 to 100 percent slopes	18K	Well drained	A	Very limited	Very limited
Rock outcrop-Despair complex, 35 to 100 percent slopes	18K			Very limited	Very limited
Water	17K			Not rated	Not rated
Thorton-Ragged-Ledeir complex, 15 to 65 percent slopes	14K	Well drained	A	Very limited	Very limited
Benzarino-Ragged-Rock outcrop complex, 35 to 100 percent slopes	11K	Well drained	D	Very limited	Very limited
Tricouni-Ragged-Easy complex, 5 to 50 percent slopes	11K	Well drained	A	Very limited	Very limited
Stehekin-Primus-Stetattle complex, 35 to 100 percent slopes	10K	Well drained	A	Very limited	Very limited
Noca-Perfect complex, 35 to 100 percent slopes	10K	Well drained	A	Very limited	Very limited
Farway-Sawtooth-Despair complex, 35 to 100 percent slopes	10K	Well drained	A	Very limited	Very limited
Chilliwack-Perfect-Terror complex, 15 to 65 percent slopes	10K	Well drained	A	Very limited	Very limited
Perfect-Spickard-Stetattle complex, 15 to 65 percent slopes	8K	Well drained	A	Very limited	Very limited
Chilliwack-Forbidden-Stetattle complex, 15 to 65 percent slopes	6K	Well drained	A	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.

Andisols

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

Inceptisols

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

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 97% 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 97% 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.