Mendocino County, Eastern Part and Southwestern Part of Trinity County, California

Survey Area CA687• 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 Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Mendocino County, Eastern Part and Southwestern Part of Trinity County, 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
Yorkville-Yorktree-Ashokawna complex, 30 to 50 percent slopes, MLRA 5	59K	Well drained	D	Very limited	Very limited
Yorkville-Ashokawna Witherell complex, 30 to 50 percent slopes, MLRA 5	59K	Moderately well drained	C	Very limited	Very limited
Sanhedrin-Kekawaka-Speaker complex, 30 to 50 percent slopes	53K	Well drained	C	Very limited	Very limited
Yorktree-Hopland-Woodin complex, 30 to 50 percent slopes	42K	Well drained	C	Very limited	Very limited
Casabonne-Wohly loams, 30 to 50 percent slopes	40K	Well drained	C	Very limited	Very limited
Shortyork-Yorkville-Witherell complex, 30 to 50 percent slopes, MLRA 5	36K	Well drained	C	Very limited	Very limited
Hopland-Sanhedrin-Kekawaka complex, 30 to 50 percent slopes	31K	Well drained	C	Very limited	Very limited
Maymen-Woodin-Etsel complex, 50 to 75 percent slopes	31K	Somewhat excessively drained	D	Very limited	Very limited
Hopland-Witherell-Ashokawna complex, 30 to 50 percent slopes, MLRA 5	30K	Well drained	C	Very limited	Very limited
Maymen-Etsel-Snook complex, 30 to 75 percent slopes, high ffd	29K	Somewhat excessively drained	D	Very limited	Very limited
Yorktree-Yorkville loams, 30 to 50 percent slopes	28K	Well drained	C	Very limited	Very limited
Maymen-Etsel-Snook complex, 30 to 75 percent slopes, low ffd	18K	Somewhat excessively drained	D	Very limited	Very limited
Area not surveyed, access denied	18K			Not rated	Not rated
Casabonne-Wohly-Pardaloe complex, 50 to 75 percent slopes, low ffd	17K	Well drained	C	Very limited	Very limited
Pardaloe-Woodin complex, 50 to 75 percent slopes, low ffd	16K	Well drained	B	Very limited	Very limited
Bearwallow-Hellman-Witherell complex, 30 to 50 percent slopes	14K	Well drained	C	Very limited	Very limited
Yorktree-Hopland-Woodin complex, 50 to 75 percent slopes	14K	Well drained	C	Very limited	Very limited
Dingman-Beaughton complex, 5 to 50 percent slopes	14K	Well drained	D	Very limited	Very limited
Maymen-Etsel-Mayacama complex, 30 to 75 percent slopes	14K	Somewhat excessively drained	D	Very limited	Very limited
Shortyork-Yorkville-Witherell complex, 15 to 30 percent slopes, MLRA 5	13K	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.

Alfisols

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

Mollisols

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

Inceptisols

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

Entisols

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

What This Means

Building & Foundations

About 96% 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 96% 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.