St. Joe Area, Idaho, Parts of Benewah and Shoshone Counties
The most common soil here is Honeyjones, on about 12% of the land: a ashy silt loam, smooth, like flour. Ahrs and Bouldercreek come next.
About 77% of the land drains well, and 4% stays wet for long stretches; groundwater comes within two feet of the surface under 19% of it.
USDA rates 99% of the land very limited for a standard septic drain field, and 99% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more, and bedrock lies within 40 inches under 8% 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 St. Joe Area, Idaho, Parts of Benewah and Shoshone Counties, 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 St. Joe Area, Idaho, Parts of Benewah and Shoshone Counties. 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 |
|---|---|---|---|---|---|
| Honeyjones-Ahrs association, very rocky, 35 to 75 percent slopes | 119K | Well drained | B | Very limited | Very limited |
| Bouldercreek-Marblecreek association, 35 to 65 percent slopes | 45K | Well drained | B | Very limited | Very limited |
| Threebear-Sly complex, 3 to 25 percent slopes | 44K | Moderately well drained | D | Very limited | Very limited |
| Bouldercreek ashy silt loam, 35 to 65 percent slopes | 42K | Well drained | B | Very limited | Very limited |
| Tigley-Hugus association, 30 to 65 percent slopes | 32K | Well drained | C | Very limited | Very limited |
| Ahrs-Pinecreek association, 25 to 75 percent slopes | 32K | Well drained | B | Very limited | Very limited |
| Honeyjones ashy silt loam, very rocky, 35 to 75 percent slopes | 30K | Well drained | B | Very limited | Very limited |
| Hobnail-Threebear complex, 5 to 25 percent slopes | 27K | Moderately well drained | C/D | Very limited | Very limited |
| Hobnail ashy silt loam, 15 to 35 percent slopes | 25K | Moderately well drained | C/D | Very limited | Very limited |
| Reggear silt loam, 3 to 20 percent slopes | 23K | Moderately well drained | C | Very limited | Very limited |
| Flewsie-Threebear silt loams, 15 to 35 percent slopes | 19K | Well drained | B | Very limited | Very limited |
| Latour-Rubble land association, 35 to 75 percent slopes | 16K | Well drained | B | Very limited | Very limited |
| Latour gravelly silt loam, 35 to 75 percent slopes | 15K | Well drained | B | Very limited | Very limited |
| Hugus silt loam, 30 to 65 percent slopes | 14K | Well drained | C | Very limited | Very limited |
| Nakarna complex, 35 to 65 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Nakarna ashy silt loam, 35 to 65 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Honeyjones-Rock outcrop complex, 65 to 85 percent slopes | 10K | Well drained | B | Very limited | Very limited |
| Lotuspoint, stony-Rock outcrop complex, 35 to 75 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Ahrs gravelly ashy silt loam, 35 to 75 percent slopes | 10K | Well drained | B | Very limited | Very limited |
| Flewsie silt loam, 35 to 65 percent slopes | 9K | 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 99% 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 99% 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.