Oregon Soil Surveys

52 survey areas

Oregon has 52 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter, making up roughly 46% of surveyed soils. Andisols — soils formed in volcanic ash, very light and porous account for another 17%.

In terms of drainage, 83% of Oregon soils are classified as well drained. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.

Soil Types

Mollisols

46% of surveyed soils

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

Andisols

17% of surveyed soils

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

Inceptisols

16% of surveyed soils

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

Aridisols

6% of surveyed soils

Dry-climate soils with low organic matter. Often have caliche layers that make excavation difficult. Low shrink-swell is good for foundations.

Alfisols

5% of surveyed soils

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

Ultisols

3% of surveyed soils

Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.

Entisols

2% of surveyed soils

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

Survey Areas

Oregon Soil Surveys

Soil Types

Survey Areas

Look Up a Specific Address