Intermountain Area, Parts of Lassen, Modoc, Shasta, and Siskiyou Counties, California
The most common soil here is Jimmerson, on about 4% of the land: a loam, a balanced mix that crumbles in your hand. Jellycamp and Gasper come next.
About 72% of the land drains well, and 8% stays wet for long stretches; groundwater comes within two feet of the surface under 9% of it.
USDA rates 95% of the land very limited for a standard septic drain field, and 68% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 9% of the land floods occasionally or more, and bedrock lies within 40 inches under 45% 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 Intermountain Area, Parts of Lassen, Modoc, Shasta, and Siskiyou Counties, California, 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 C (slow infiltration, moderate runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Intermountain Area, Parts of Lassen, Modoc, Shasta, and Siskiyou Counties, California. 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 |
|---|---|---|---|---|---|
| Loveness-Fleener complex, 2 to 15 percent slopes | 46K | Well drained | C | Somewhat limited | Very limited |
| Lava flows-Gassaway complex, 2 to 15 percent slopes | 37K | Somewhat limited | Somewhat limited | ||
| Jimmerson loam-Jimmerson stony sandy loam complex, 2 to 15 percent slopes | 34K | Well drained | C | Somewhat limited | Very limited |
| Scarface-Gasper complex, 2 to 15 percent slopes | 28K | Well drained | C | Somewhat limited | Very limited |
| Jellycamp-Ollierivas complex, 2 to 9 percent slopes | 25K | Moderately well drained | D | Very limited | Very limited |
| Neuns-Kindig complex, 50 to 75 percent slopes | 25K | Well drained | C | Very limited | Very limited |
| Jellycamp-Lassen-Longcreek complex, 2 to 15 percent slopes | 22K | Well drained | D | Very limited | Very limited |
| Chirpchatter-Hunsinger complex, 2 to 15 percent slopes | 20K | Well drained | B | Somewhat limited | Very limited |
| Neer-Ponto complex, 2 to 30 percent slopes | 19K | Well drained | A | Very limited | Very limited |
| Jellycamp-Vansickle complex, very cobbly loam, 2 to 9 percent slopes | 18K | Moderately well drained | D | Very limited | Very limited |
| Hunsinger-Chirpchatter complex, 30 to 50 percent slopes | 17K | Well drained | C | Very limited | Very limited |
| Jellico-Splawn complex, 15 to 30 percent slopes | 15K | Well drained | C | Very limited | Very limited |
| Burney-Arkright complex, 2 to 9 percent slopes | 15K | Well drained | C | Not limited | Very limited |
| Wyntoon sandy loam, 2 to 15 percent slopes | 15K | Well drained | C | Somewhat limited | Very limited |
| Bieber-Modoc complex, 0 to 5 percent slopes | 15K | Moderately well drained | D | Very limited | Very limited |
| Obie-Mounthat complex, 30 to 50 percent slopes | 15K | Well drained | A | Very limited | Very limited |
| Gasper-Scarface complex, 15 to 30 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Water | 13K | D | Not rated | Not rated | |
| Witcher-Gosch complex, 15 to 30 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Lava flows | 12K | 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 68% 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 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.