Carbon County Area, Montana
The most common soil here is Travessilla, on about 5% of the land: a stony sandy loam, gritty and crumbly. Absarokee and Heath come next.
About 81% of the land drains well.
USDA rates 66% of the land very limited for a standard septic drain field, and 54% 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 50% 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 Carbon County Area, 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 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 Carbon County Area, 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 |
|---|---|---|---|---|---|
| Rock outcrop-Travessilla complex, steep | 75K | D | Not rated | Not rated | |
| Macar-Cabba clay loams, 8 to 15 percent slopes | 44K | Well drained | B | Somewhat limited | Somewhat limited |
| Limestone outcrop | 44K | D | Not rated | Not rated | |
| Midway-Travessilla association, steep | 42K | Well drained | D | Very limited | Very limited |
| Rentsac-Rock outcrop complex, steep | 34K | Well drained | B | Very limited | Very limited |
| Midway-Travessilla association, hilly | 29K | Well drained | D | Very limited | Very limited |
| Sandstone outcrop | 27K | D | Not rated | Not rated | |
| Charlos loam, 0 to 2 percent slopes | 25K | Well drained | B | Not limited | Very limited |
| Hanson association, very steep | 25K | Well drained | B | Very limited | Very limited |
| Wayden-Castner association, steep | 25K | Well drained | D | Very limited | Very limited |
| Heath clay loam, 8 to 15 percent slopes | 23K | Well drained | C | Very limited | Very limited |
| Heath-Bynum association, steep | 22K | Well drained | C | Very limited | Very limited |
| Shale outcrop | 18K | D | Not rated | Not rated | |
| Absarokee clay loam, 4 to 8 percent slopes | 18K | Well drained | C | Very limited | Very limited |
| Sinnigam channery clay loam, moderately steep | 17K | Well drained | C | Very limited | Very limited |
| Wayden-Cabba association, steep | 16K | Well drained | D | Very limited | Very limited |
| Lismas clay, hilly | 14K | Well drained | D | Very limited | Very limited |
| Heldt silty clay loam, 0 to 2 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Lap-Rock outcrop association, moderately steep | 13K | Well drained | D | Very limited | Very limited |
| Absarokee clay loam, 8 to 15 percent slopes | 12K | Well drained | C | 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 54% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 66% 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.