Jefferson County, Idaho
The most common soil here is Terreton, on about 13% of the land: a silty clay loam, smooth and slightly sticky. Pancheri and Matheson come next.
About 86% of the land drains well, and 4% stays wet for long stretches; groundwater comes within two feet of the surface under 2% of it.
USDA rates 85% of the land very limited for a standard septic drain field, and 51% 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 39% 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 Jefferson County, Idaho, 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 D (very slow infiltration, high runoff). The most common soil order is Aridisols — dry-climate soils with limited organic matter and often calcium carbonate accumulation. 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 Jefferson County, Idaho. 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 |
|---|---|---|---|---|---|
| Terreton silty clay loam | 52K | Well drained | D | Very limited | Very limited |
| Aecet, very stony surface-Rock outcrop-Bereniceton complex | 46K | Well drained | C | Very limited | Very limited |
| Grassy Butte-Rock outcrop complex | 31K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Malm-Rock outcrop complex | 30K | Well drained | D | Very limited | Very limited |
| Pancheri silt loam, 2 to 4 percent slopes | 27K | Well drained | B | Not limited | Very limited |
| Terreton-Zwiefel complex | 27K | Well drained | D | Very limited | Very limited |
| Mathon-Rock outcrop-Modkin complex | 24K | Well drained | A | Very limited | Very limited |
| Bereniceton-Rock outcrop-Aecet complex | 16K | Well drained | C | Somewhat limited | Very limited |
| Bondranch-Rock outcrop complex | 16K | Well drained | D | Very limited | Very limited |
| Matheson-Malm loams | 15K | Well drained | A | Somewhat limited | Somewhat limited |
| Bereniceton-Terreton-Aecet complex | 14K | Well drained | C | Very limited | Very limited |
| Tan gravelly loam, 0 to 1 percent slopes | 14K | Well drained | C | Not limited | Very limited |
| Pancheri silt loam, 4 to 8 percent slopes | 13K | Well drained | B | Not limited | Very limited |
| Pancheri silt loam, 0 to 2 percent slopes | 13K | Well drained | B | Not limited | Very limited |
| Terreton loamy sand | 12K | Well drained | C | Very limited | Very limited |
| Blackfoot silt loam, drained | 12K | Moderately well drained | B | Somewhat limited | Somewhat limited |
| Grassy Butte sand, 2 to 20 percent slopes | 12K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Xeric Torrifluvents | 11K | Excessively drained | A | Very limited | Very limited |
| Matheson loamy sand, 2 to 8 percent slopes | 10K | Well drained | A | Not limited | Not limited |
| Diston loamy sand, 0 to 4 percent slopes | 10K | Somewhat excessively drained | A | Not 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 51% of soils are rated "very limited" for dwellings with basements. Specific challenges include flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 85% 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
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.