Soil series profile
Lismas soil series
Lismas is a well drained soil with a clay surface, mapped on 613,433 acres in 19 counties across 5 states. Hydrologic group D.
- Drainage class
- Well drained >99% of mapped acres
- Hydrologic group
- D >99% of mapped acres
- Typical topsoil pH
- 7.2 neutral · range 7.0–7.5
- Mapped area
- 613k acres in 19 counties, 5 states
Typical Lismas profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–5 in (A) | Clay | 7.0 | 60% | 11% | 2% |
| 5–9 in (C1) | Clay | 6.5 | 60% | 11% | 0.8% |
| 9–14 in (C2) | Parachannery clay | 6.4 | 60% | 11% | 0.6% |
| 14–79 in (Cr) | Bedrock | 6.0 | 55% | Not reported | 0.25% |
What this means
What Lismas soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Lismas soils is neutral: pH 7.2 (most land between 7.0 and 7.5), the range most vegetables, flowers and lawn grasses prefer.
Clayey topsoil covers 95% of mapped Lismas acres. Clay holds water and nutrients but drains slowly and compacts if worked wet: add compost, avoid tilling soggy soil and consider raised beds. The most common surface texture is clay (89% of mapped Lismas acres).
>99% of mapped Lismas acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On >99% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.
For a septic system
For conventional septic absorption fields, NRCS rates >99% of the acres in mapped Lismas soils very limited, 0% somewhat limited and 0% not limited.
Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Lismas soil is found
Mapped acres
Lismas is mapped in Montana, South Dakota, Wyoming, Colorado and Nebraska.
| County | Acres | Share of county land |
|---|---|---|
| Butte County, SD | 148,699 | 10.4% |
| Big Horn County, MT | 136,685 | 3.1% |
| Yellowstone County, MT | 109,960 | 6.5% |
| Meade County, SD | 89,014 | 4.0% |
| Treasure County, MT | 30,924 | 4.9% |
| Campbell County, WY | 28,052 | 0.9% |
| Carbon County, MT | 13,870 | 1.1% |
| Elbert County, CO | 13,856 | 1.2% |
| Harding County, SD | 12,060 | 0.7% |
| Wibaux County, MT | 11,668 | 2.0% |
| Judith Basin County, MT | 5,977 | 0.7% |
| Crook County, WY | 5,153 | 0.3% |
| Fall River County, SD | 2,280 | 0.2% |
| Pennington County, SD | 1,575 | 0.1% |
| Dawes County, NE | 1,148 | 0.1% |
| Prowers County, CO | 985 | 0.1% |
| Sioux County, NE | 788 | 0.1% |
| Lawrence County, SD | 604 | 0.1% |
| Weston County, WY | 134 | 0.0% |
Septic absorption fields
NRCS rating, share of Lismas acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 99.9% |
| Not rated | 0.1% |
Drainage, water table and flooding
Share of Lismas acres
- Depth to seasonal high water table
- About 1.2 feet (14 in) (median where reported); within 18 inches on <1% of acres.
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 12–28% (median 25%).
- Topsoil organic matter
- Median 1.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 99.8% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.1% |
| Very poorly drained | 0.0% |
| Not rated | 0.1% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 99.8% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.1% |
| Not rated | 0.1% |
Sources & data dates
- Source
- USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
- Data date
- SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
- Scope
- All map unit components named Lismas (component kind "Series") in SSURGO: 613,433 acres.
- Method
- Shares are by mapped acres of Lismas components. The profile comes from the single largest Lismas component. Full methodology.