State soil summary
Soil types in Oregon
The most widespread soil series in Oregon are Lapine, Raz, Lickskillet. Pick a county below, or enter a ZIP code for the county you live in.
- Well or moderately well drained
- 82% of mapped land
- Typical topsoil pH
- 6.7 neutral · most land 5.3–7.6
- Septic fields very limited
- 85% <1% not limited
- Subject to flooding
- 3% of land, any frequency
Oregon counties
8 county reports, by population
| County | Most common soil | Well drained | Topsoil pH | Septic very limited |
|---|---|---|---|---|
| Multnomah County | Zygore | 61% | 5.8 | 85% |
| Washington County | Olyic | 79% | 5.8 | 97% |
| Clackamas County | Jory | 82% | 5.6 | 96% |
| Lane County | Bohannon | 89% | 5.6 | 97% |
| Marion County | Woodburn | 77% | 5.8 | 94% |
| Jackson County | Vannoy | 91% | 6.1 | 94% |
| Deschutes County | Shanahan | 87% | 7.0 | 95% |
| Linn County | Dayton | 75% | 5.6 | 97% |
What this means
What Oregon soils mean for gardens, lawns and septic systems
For gardens
Typical topsoil in Oregon is neutral: pH 6.7 (most land between 5.3 and 7.6), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 77% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (12% of the land).
82% of the land is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 64% of the land, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.
For septic systems
For conventional septic absorption fields, NRCS rates 85% of the land in Oregon very limited, 4% somewhat limited and <1% not limited (10% not rated, such as urban land, pits or water).
Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Statewide mix
Share of all mapped land
Drainage
Show as a table
| Category | Share of land |
|---|---|
| Excessively drained | 2.4% |
| Somewhat excessively drained | 4.8% |
| Well drained | 71.6% |
| Moderately well drained | 3.4% |
| Somewhat poorly drained | 2.4% |
| Poorly drained | 2.8% |
| Very poorly drained | 0.8% |
| Not rated | 11.8% |
Septic absorption fields
Show as a table
| Category | Share of land |
|---|---|
| Not limited | 0.5% |
| Somewhat limited | 4.4% |
| Very limited | 85.3% |
| Not rated | 9.8% |
Topsoil pH
Show as a table
| Category | Share of land |
|---|---|
| Strongly acidic (below 5.5) | 10.4% |
| Moderately to slightly acidic (5.5–6.4) | 23.0% |
| Near neutral (6.5–7.3) | 40.4% |
| Alkaline (7.4 and up) | 13.8% |
| Not reported | 12.4% |
Sources & data dates
- Source
- USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
- Data date
- SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
- Scope
- Oregon: 57,211,640 acres of mapped land in 36 counties, pooled (not an average of county figures).
- Method
- Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.