Pinnacles National Monument, California

Survey Area CA788• California

The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate 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 Pinnacles National Monument, 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
Ordeal-Longsfolly-Passion complex, 9 to 50 percent slopes	4K	Somewhat excessively drained	A	Very limited	Very limited
Backdoor-Tuborcio complex, 20 to 70 percent slopes	4K	Well drained	C	Very limited	Very limited
Ordeal-Passion-Badlands association, 50 to 100 percent slopes	3K	Somewhat excessively drained	B	Very limited	Very limited
Backdoor-Tuborcio complex, 35 to 50 percent slopes	2K	Well drained	C	Very limited	Very limited
Ordeal-Tuborcio-Passion complex, 20 to 50 percent slopes	2K	Somewhat excessively drained	B	Very limited	Very limited
Chalone-Knuckle-Firstsister complex, 50 to 70 percent slopes	2K	Well drained	C	Very limited	Very limited
Knuckle-Burgundy-Argixerolls complex, 20 to 70 percent slopes	2K	Well drained	D	Very limited	Very limited
Rock outcrop-Highpeaks-Burgundy complex, 35 to 100 percent slopes	1K	Well drained	D	Very limited	Very limited
Chalone-Firstsister-Highpeaks complex, 50 to 70 percent slopes	1K	Well drained	C	Very limited	Very limited
Tuborcio sandy loam, 35 to 50 percent slopes	790	Well drained	C	Very limited	Very limited
Rock outcrop-Highpeaks-Chalone complex, 35 to 50 percent slopes	730	Well drained	D	Very limited	Very limited
Chalone-Knuckle-Rock outcrop complex, 35 to 50 percent slopes	651	Well drained	D	Very limited	Very limited
Argixerolls-Rock outcrop-Chalone complex, 35 to 50 percent slopes	623	Well drained	C	Very limited	Very limited
Casino-Argixerolls complex, 50 to 70 percent slopes	436	Moderately well drained	D	Very limited	Very limited
Highpeaks-Rock outcrop complex, 35 to 50 percent slopes	282	Well drained	D	Very limited	Very limited
Pinnacles coarse sandy loam, 5 to 30 percent slopes	267	Well drained	C	Very limited	Very limited
Toags-Oxyaquic Haploxerolls-Riverwash complex, 0 to 2 percent slopes	254	Somewhat excessively drained	A	Not limited	Very limited
Pinnacles coarse sandy loam, 30 to 75 percent slopes	240	Well drained	D	Very limited	Very limited
Teapot-Rock outcrop complex, 35 to 50 percent slopes	191	Well drained	B	Very limited	Very limited
Tuborcio loam, 2 to 20 percent slopes	185	Well drained	C	Somewhat 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.

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 98% 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 100% 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.