Idaho Panhandle National Forest, Idaho-Washington-Montana
The most common soil here is Bouldercreek, on about 16% of the land: a ashy silt loam, smooth, like flour. Pearsoncreek and Kintla come next.
About 83% of the land drains well; groundwater comes within two feet of the surface under 14% of it.
USDA rates 95% of the land very limited for a standard septic drain field, and 94% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: bedrock lies within 40 inches under 13% 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 Idaho Panhandle National Forest, Idaho-Washington-Montana, 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 B (moderate infiltration). The most common soil order is Andisols — soils formed in volcanic ash, very light and porous. 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 Idaho Panhandle National Forest, Idaho-Washington-Montana. 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 |
|---|---|---|---|---|---|
| Bouldercreek family, weakly weathered metasedimentary belt geology, mountain slopes, north aspects | 156K | Well drained | B | Very limited | Very limited |
| Bouldercreek-Ahrs families, complex, weakly weathered metasedimentary belt geology, mountain slopes, south aspects | 139K | Well drained | B | Very limited | Very limited |
| Water | 76K | Not rated | Not rated | ||
| Bouldercreek-Humic Udivitrands families, complex, weakly weathered metasedimentary belt geology, dissected stream breaklands, north aspects | 74K | Well drained | B | Very limited | Very limited |
| Kintla-Vaywood-Kintla families, slightly acid subsoil complex, weakly weathered high elevation broadly convex mountain slopes, metasedimentary belt geology, north aspects | 70K | Well drained | B | Very limited | Very limited |
| Honeyjones family, weakly weathered metasedimentary belt geology, stream breaklands, north aspects | 67K | Well drained | B | Very limited | Very limited |
| Bouldercreek-Humic Udivitrands families, complex, weakly weathered belt geology, lower sideslopes toeslopes and stream bottoms of incised drainages along slopes, north aspects | 60K | Well drained | B | Very limited | Very limited |
| Ahrs family-Rock outcrop-Typic Vitrixerands family, complex, weakly weathered metasedimentary belt geology, mountain slopes, south aspects, dry | 60K | Well drained | B | Very limited | Very limited |
| Vaywood-Kintla families, complex, weakly weathered high elevation broadly convex mountain slopes, metasedimentary belt geology, south aspects | 59K | Well drained | B | Very limited | Very limited |
| Typic Vitrixerands-Honeyjones families, complex, weakly weathered metasedimentary belt geology, dissected stream breaklands, south aspects | 59K | Well drained | B | Very limited | Very limited |
| Andic Humudepts-Humic Udivitrands-Pearsoncreek families, dense substratum complex, glaciated mountain slopes, granitic geology, south aspects | 54K | Well drained | B | Very limited | Very limited |
| Glaciercreek-Humic Udivitrands-Pearsoncreek families, dense substratum complex, glaciated mountain slopes, granitic geology, north aspects | 53K | Moderately well drained | D | Very limited | Very limited |
| Hugus-Honeyjones families, complex, moderately weathered metasedimentary belt geology, mountain slopes, north aspects | 51K | Well drained | B | Very limited | Very limited |
| Typic Vitrixerands family-Rock outcrop-Lotuspoint family, complex, weakly weathered metasedimentary belt geology, stream breaklands, south aspects, dry | 50K | Well drained | B | Very limited | Very limited |
| Highfalls-Pearsoncreek-Newbell families, complex, glaciated mountain slopes, belt geology, south aspects | 50K | Well drained | B | Very limited | Very limited |
| Typic Vitrixerands-Ahrs families, complex, weakly weathered metasedimentary belt geology, stream breaklands, south aspects | 47K | Well drained | B | Very limited | Very limited |
| Bouldercreek-Humic Udivitrands families, complex, weakly weathered belt geology, lower sideslopes toeslopes and stream bottoms of incised drainages along slopes, south aspects | 45K | Well drained | B | Very limited | Very limited |
| Caribouridge-Stien families, complex, outwash plains of mixed geology | 43K | Well drained | B | Very limited | Very limited |
| Highfalls-Pearsoncreek families, complex, glaciated mountain slopes, belt geology, north aspects, 15 to 45 percent slopes | 43K | Well drained | B | Very limited | Very limited |
| Kintla-Kintla families, very gravelly medial silt loam complex, weakly weathered high elevation broadly convex mountain slopes, metasedimentary belt geology, south aspects, sparsely timbered | 38K | Well drained | B | 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 94% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 95% 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.