Fallon County, Montana
The most common soil here is Cabbart, on about 12% of the land: a loam, a balanced mix that crumbles in your hand. Cambeth and Neldore come next.
About 97% of the land drains well.
USDA rates 66% of the land very limited for a standard septic drain field, and 43% 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 59% 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 Fallon County, 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 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 Fallon County, 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 |
|---|---|---|---|---|---|
| Cabbart-Rock outcrop-Delpoint complex, 15 to 50 percent slopes | 72K | Well drained | D | Very limited | Very limited |
| Cabbart-Cambeth silt loams, 8 to 15 percent slopes | 57K | Well drained | D | Very limited | Very limited |
| Neldore clay, 4 to 15 percent slopes | 36K | Well drained | D | Very limited | Very limited |
| Eapa loam, 2 to 8 percent slopes | 35K | Well drained | B | Somewhat limited | Somewhat limited |
| Archin loam, 2 to 8 percent slopes | 26K | Well drained | C | Not limited | Not limited |
| Kremlin loam, warm, 2 to 8 percent slopes | 23K | Well drained | B | Not limited | Somewhat limited |
| Neldore-Bascovy clays, 4 to 15 percent slopes | 22K | Well drained | D | Very limited | Very limited |
| Cambeth-Cabbart silt loams, 2 to 8 percent slopes | 22K | Well drained | C | Somewhat limited | Very limited |
| Delpoint-Cabbart complex, 8 to 15 percent slopes | 22K | Well drained | C | Somewhat limited | Very limited |
| Havre loam, 0 to 2 percent slopes | 20K | Well drained | B | Very limited | Somewhat limited |
| Gerdrum clay loam, 2 to 8 percent slopes | 20K | Well drained | D | Very limited | Not limited |
| Lonna silt loam, 2 to 8 percent slopes | 19K | Well drained | C | Not limited | Very limited |
| Chinook sandy loam, 2 to 8 percent slopes | 19K | Well drained | A | Not limited | Not limited |
| Gerdrum-Absher complex, 2 to 8 percent slopes | 18K | Well drained | D | Very limited | Not limited |
| Blacksheep-Twilight fine sandy loams, complex, 8 to 15 percent slopes | 17K | Well drained | D | Somewhat limited | Very limited |
| Archin-Absher complex, 2 to 8 percent slopes | 16K | Well drained | D | Somewhat limited | Not limited |
| Lonna-Cabbart silt loams, 8 to 25 percent slopes | 16K | Well drained | B | Somewhat limited | Somewhat limited |
| Busby-Twilight-Blacksheep fine sandy loams, 8 to 35 percent slopes | 14K | Well drained | A | Very limited | Very limited |
| Cabbart silt loam, 4 to 15 percent slopes | 14K | Well drained | D | Very limited | Very limited |
| Bonfri-Cabbart loams, 8 to 15 percent slopes | 13K | Well drained | C | Somewhat 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 43% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
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.