Olympic National Park, Washington
The most common soil here is Skookumcreek, on about 13% of the land: a gravelly loam, a balanced mix that crumbles in your hand. Bonjonpass and Sentinelpeak come next.
About 90% of the land drains well; groundwater comes within two feet of the surface under 49% of it.
USDA rates 98% of the land very limited for a standard septic drain field, and 98% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 2% of the land floods occasionally or more, and bedrock lies within 40 inches under 22% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Olympic National Park, Washington, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). The most common soil order is Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Olympic National Park, Washington. 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 |
|---|---|---|---|---|---|
| Skookumcreek-Bonjonpass-Mountscott complex, 0 to 100 percent slopes | 216K | Well drained | A | Very limited | Very limited |
| Mountmystery-Ignarcreek-Lakedilly complex, 15 to 100 percent slopes | 72K | Well drained | A | Very limited | Very limited |
| Hungrycreek-Nonamecreek-Lakedilly complex, 15 to 100 percent slopes | 65K | Well drained | A | Very limited | Very limited |
| Mountdeception-Irely complex, 35 to 100 percent slopes | 60K | Well drained | A | Very limited | Very limited |
| Rock outcrop-Rubble land complex, 15 to 100 percent slopes | 50K | Very limited | Very limited | ||
| Bonjonpass-Skookumcreek-Lapoetcreek complex, 0 to 65 percent slopes | 47K | Well drained | A | Very limited | Very limited |
| Sentinelpeak gravelly loam, 35 to 100 percent slopes | 43K | Well drained | A | Very limited | Very limited |
| Jolleycreek-Saghalie complex, 0 to 60 percent slopes | 33K | Well drained | A | Very limited | Very limited |
| Grandpass-Marmotlake-Allincreek,dry complex, 40 to 100 percent slopes | 31K | Well drained | A | Very limited | Very limited |
| Lollah-Hungrycreek-Allincreek complex, 15 to 100 percent slopes | 26K | Well drained | A | Very limited | Very limited |
| Catpeak-Allincreek-Rubble land complex, 0 to 100 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Sunnybrook-Mountscott complex, 0 to 100 percent slopes | 21K | Well drained | A | Very limited | Very limited |
| Mountstone-Mountfromme,cool,dry complex, 40 to 100 percent slopes | 20K | Well drained | A | Very limited | Very limited |
| Catpeak-Allincreek-Hungrycreek complex, 0 to 60 percent slopes | 19K | Well drained | A | Very limited | Very limited |
| Allincreek,dry-Rubble land complex, 0 to 100 percent slopes | 15K | Well drained | D | Very limited | Very limited |
| Mountmeany-Marymere complex, 0 to 10 percent slopes | 14K | Well drained | A | Very limited | Very limited |
| Water | 13K | Not rated | Not rated | ||
| Hatana-Cragcreek complex, 0 to 10 percent slopes | 13K | Well drained | A | Very limited | Very limited |
| Palix-Ozette complex, 5 to 25 percent slopes | 12K | Well drained | B | Very limited | Very limited |
| Sentinelpeak gravelly loam, 15 to 60 percent slopes | 11K | Well drained | A | 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.
What This Means
Building & Foundations
About 98% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 98% 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.