Soil survey area

San Bernardino National Forest Area, California

Survey Area CA777• California

The short version

The most common soil here is Lithic Xerorthents, on about 11% of the land. Pacifico family and Trigo family come next.

About 97% of the land drains well.

USDA rates 99% of the land very limited for a standard septic drain field, and 88% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 2% of the land floods occasionally or more, and bedrock lies within 40 inches under 80% of it.

Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.

The biggest mapped areas

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 Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 San Bernardino 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 family-Lithic Xerorthents, warm complex, 50 to 75 percent slopes	74K	Somewhat excessively drained	D	Very limited	Very limited
Rock outcrop, 30 to 100 percent slopes	41K	Excessively drained	D	Very limited	Very limited
Springdale family-Lithic Xerorthents association, dry, 50 to 75 percent slopes	31K	Somewhat excessively drained	A	Very limited	Very limited
Wapi-Pacifico families, dry-Rock outcrop complex, 50 to 75 percent slopes	29K	Somewhat excessively drained	D	Very limited	Very limited
Wapi-Pacifico families, dry-Rock outcrop complex, 30 to 50 percent slopes	28K	Somewhat excessively drained	D	Very limited	Very limited
Lithic Xerorthents-Rock outcrop complex, 50 to 100 percent slopes	28K	Excessively drained	D	Very limited	Very limited
Lithic Xerorthents, warm-Rock outcrop complex, 50 to 100 percent slopes	27K	Excessively drained	D	Very limited	Very limited
Lithic Xerorthents-Springdale family-Rubble land association, 50 to 100 percent slopes	26K	Excessively drained	D	Very limited	Very limited
Wapi-Pacifico families-Rock outcrop complex, 50 to 75 percent slopes	23K	Somewhat excessively drained	D	Very limited	Very limited
Pacifico-Wapi families complex, 30 to 50 percent slopes	23K	Somewhat excessively drained	D	Very limited	Very limited
Wapi-Pacifico families, dry-Rock outcrop complex, 15 to 30 percent slopes	21K	Somewhat excessively drained	D	Very limited	Very limited
Lithic Xerorthents, cool-Rock outcrop complex, 50 to 100 percent slopes	20K	Excessively drained	D	Very limited	Very limited
Wapal family-Lithic Xerorthents, cool association, 50 to 75 percent slopes	18K	Somewhat excessively drained	A	Very limited	Very limited
Typic Xerorthents, warm-Typic Haploxeralfs-Badland complex, 30 to 100 percent slopes	17K	Somewhat excessively drained	B	Very limited	Very limited
Trigo family-Lithic Xerorthents, warm complex, 30 to 50 percent slopes	17K	Somewhat excessively drained	D	Very limited	Very limited
Olete-Goulding families-Rubble land association, 50 to 100 percent slopes	16K	Well drained		Very limited	Very limited
Osito-Modesto families association, 30 to 50 percent slopes	16K	Well drained	D	Very limited	Very limited
Pacifico-Preston families complex, 30 to 50 percent slopes	15K	Somewhat excessively drained	D	Very limited	Very limited
Morical-Wind River families complex, 30 to 50 percent slopes	15K	Well drained	C	Very limited	Very limited
Morical-Wind River families complex, 15 to 30 percent slopes	15K	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.

Mollisols

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

Entisols

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

Inceptisols

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

Alfisols

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

What This Means

Building & Foundations

About 88% 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 99% 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.