Angeles National Forest Area, California

Survey Area CA776• California

The dominant drainage class is Somewhat excessively 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 Angeles National Forest Area, California. 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
Trigo, granitic substratum-Exchequer families-Rock outcrop complex, 60 to 100 percent slopes	53K	Somewhat excessively drained	D	Very limited	Very limited
Caperton-Trigo, granitic substratum-Lodo families complex, 50 to 85 percent slopes	40K	Well drained	D	Very limited	Very limited
Rock outcrop-Chilao family-Haploxerolls, warm association, 15 to 120 percent slopes	36K		D	Very limited	Very limited
Lodo-Modesto families complex, 30 to 70 percent slopes	28K	Somewhat excessively drained	D	Very limited	Very limited
Rock outcrop-Lithic Xerorthents-Rubble land association, 60 to 120 percent slopes	23K	Excessively drained	D	Very limited	Very limited
Pismo-Chilao-Shortcut families complex, 45 to 80 percent slopes	22K	Somewhat excessively drained	D	Very limited	Very limited
Trigo-Calleguas families-Haploxeralfs complex, 30 to 70 percent slopes	20K	Well drained	D	Very limited	Very limited
Caperton-Capistrano families complex, 35 to 80 percent slopes	20K	Well drained	D	Very limited	Very limited
Stukel-Sur-Winthrop families complex, 60 to 100 percent slopes	19K	Somewhat excessively drained	D	Very limited	Very limited
Trigo, granitic substratum-Exchequer families-Rock outcrop complex, 30 to 60 percent slopes	18K	Somewhat excessively drained	D	Very limited	Very limited
Bakeoven family-Lithic Xerorthents-Sur family, moderately deep complex, 45 to 80 percent slopes	18K	Well drained	D	Very limited	Very limited
Pismo family-Rock outcrop complex, 50 to 80 percent slopes	18K	Somewhat excessively drained	D	Very limited	Very limited
Stonyford-Millsholm families complex, 30 to 70 percent slopes	16K	Well drained	D	Very limited	Very limited
Pismo-Trigo, dry-Exchequer, dry families complex, 30 to 70 percent slopes	16K	Somewhat excessively drained	D	Very limited	Very limited
Rubble land-Rock outcrop complex, 50 to 100 percent slopes	14K	Excessively drained		Very limited	Very limited
Waterman-Springdale-Pacifico families complex, 30 to 70 percent slopes	13K	Somewhat excessively drained	D	Very limited	Very limited
Typic Xerorthents, warm, 55 to 90 percent slopes	12K	Excessively drained	A	Very limited	Very limited
Vista-Trigo, granitic substratum-Modesto families complex, 40 to 70 percent slopes	12K	Well drained	D	Very limited	Very limited
Trigo family, dry-Lithic Xerorthents, warm complex, 50 to 80 percent slopes	12K	Somewhat excessively drained	B	Very limited	Very limited
Haploxerols, shallow-Lithic Xerorthents, warm complex, 45 to 75 percent slopes	12K	Well drained	D	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.

Entisols

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

Mollisols

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

Alfisols

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

Inceptisols

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

What This Means

Building & Foundations

About 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, sandy or gravelly soils with low bearing capacity. A geotechnical assessment is recommended before building.

Septic Systems

About 100% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.