Soil series profile
Zygore soil series
Zygore is a well drained soil with a gravelly loam surface, mapped on 91,571 acres in 4 counties across 2 states. Hydrologic group B.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- B 72% of mapped acres
- Typical topsoil pH
- 5.8 moderately acidic · range 5.6–5.9
- Mapped area
- 92k acres in 4 counties, 2 states
Typical Zygore profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–14 in (H1) | Gravelly loam | 5.6 | 14% | 45% | 2.5% |
| 14–37 in (H2) | Very gravelly loam | 5.3 | 14% | 45% | 1.25% |
| 37–60 in (H3) | Extremely gravelly silt loam | 5.0 | 14% | 30% | 0.25% |
What this means
What Zygore soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Zygore soils is moderately acidic: pH 5.8 (most land between 5.6 and 5.9). Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 99% of mapped Zygore acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is gravelly loam (99% of mapped Zygore acres).
100% of mapped Zygore acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
28% of mapped acres is in hydrologic group A, where water soaks in fast. Lawns there dry out quickly; deeper, less frequent watering and organic matter help.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Zygore soils very limited, 0% somewhat limited and 0% not limited.
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.
Where Zygore soil is found
Mapped acres
Zygore is mapped in Oregon and Washington.
| County | Acres | Share of county land |
|---|---|---|
| Skamania County, WA | 25,303 | 1.5% |
| Multnomah County, OR | 22,524 | 8.4% |
| Clackamas County, OR | 17,661 | 3.2% |
| Marion County, OR | 2,692 | 0.5% |
Septic absorption fields
NRCS rating, share of Zygore acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 100.0% |
Drainage, water table and flooding
Share of Zygore acres
- Depth to seasonal high water table
- None reported within about 6.5 feet (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 18–70% (median 48%).
- Topsoil organic matter
- Median 8%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 28.2% |
| B: moderate infiltration | 71.8% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 0.0% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.0% |
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
- All map unit components named Zygore (component kind "Series") in SSURGO: 91,571 acres.
- Method
- Shares are by mapped acres of Zygore components. The profile comes from the single largest Zygore component. Full methodology.