Soil series profile
Tetonka soil series
Tetonka is a poorly drained soil with a silt loam surface, mapped on 608,855 acres in 38 counties across 3 states. Hydrologic group C/D.
- Drainage class
- Poorly drained 100% of mapped acres
- Hydrologic group
- C/D >99% of mapped acres
- Typical topsoil pH
- 6.5 slightly acidic · range 6.5–6.5
- Mapped area
- 609k acres in 38 counties, 3 states
Typical Tetonka profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–8 in (Ap) | Silt loam | 6.5 | 23% | 13% | 5% |
| 8–16 in (E) | Silt loam | 6.8 | 25% | 11% | 2% |
| 16–39 in (Bt) | Silty clay | 7.0 | 42% | 12% | 1.5% |
| 39–46 in (Cg1) | Silty clay loam | 7.2 | 34% | 12% | 0.25% |
| 46–79 in (2Cg2) | Clay loam | 7.9 | 28% | 38% | 0.25% |

What this means
What Tetonka soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Tetonka soils is slightly acidic: pH 6.5, the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers >99% of mapped Tetonka acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (91% of mapped Tetonka acres).
100% of mapped Tetonka acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.
For lawns and yards
On 100% 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.
A seasonal high water table comes within 18 inches of the surface on 100% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Tetonka 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 Tetonka soil is found
Mapped acres
Tetonka is mapped in South Dakota, Nebraska and Iowa.
| County | Acres | Share of county land |
|---|---|---|
| Hutchinson County, SD | 78,368 | 9.8% |
| Hanson County, SD | 78,364 | 9.8% |
| Hand County, SD | 51,825 | 5.6% |
| Beadle County, SD | 46,230 | 5.7% |
| Miner County, SD | 35,064 | 10.0% |
| Sanborn County, SD | 34,757 | 9.6% |
| Charles Mix County, SD | 30,397 | 4.4% |
| Douglas County, SD | 28,286 | 10.2% |
| Bon Homme County, SD | 24,036 | 6.6% |
| Lincoln County, SD | 22,497 | 6.1% |
| Davison County, SD | 19,938 | 7.7% |
| McCook County, SD | 19,409 | 5.3% |
| Turner County, SD | 17,694 | 4.5% |
| Kingsbury County, SD | 15,188 | 2.9% |
| Aurora County, SD | 13,379 | 3.0% |
| Clay County, SD | 11,776 | 4.4% |
| Potter County, SD | 11,438 | 2.1% |
| Jerauld County, SD | 11,162 | 3.3% |
| Sully County, SD | 10,358 | 1.6% |
| Yankton County, SD | 9,716 | 2.9% |
| Spink County, SD | 8,640 | 0.9% |
| Lake County, SD | 8,179 | 2.3% |
| Hyde County, SD | 5,411 | 1.0% |
| Hughes County, SD | 4,993 | 1.1% |
| Minnehaha County, SD | 4,604 | 0.9% |
| Walworth County, SD | 2,059 | 0.5% |
| Clark County, SD | 1,691 | 0.3% |
| Brule County, SD | 1,011 | 0.1% |
| Buffalo County, SD | 1,011 | 0.1% |
| Moody County, SD | 866 | 0.3% |
| Faulk County, SD | 323 | 0.1% |
| Union County, SD | 106 | 0.0% |
| Cedar County, NE | 31 | 0.0% |
| Boyd County, NE | 20 | 0.0% |
| Knox County, NE | 14 | 0.0% |
| Lyon County, IA | 10 | 0.0% |
| Brookings County, SD | 5 | 0.0% |
| Edmunds County, SD | 1 | 0.0% |
Septic absorption fields
NRCS rating, share of Tetonka acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 100.0% |
Drainage, water table and flooding
Share of Tetonka acres
- Depth to seasonal high water table
- About 0 inches (median where reported); within 18 inches on 100% of acres.
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 1–1% (median 1%).
- Topsoil organic matter
- Median 5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 100.0% |
| Very poorly drained | 0.0% |
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) | 0.5% |
| 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 | 99.5% |
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 Tetonka (component kind "Series") in SSURGO: 608,855 acres.
- Method
- Shares are by mapped acres of Tetonka components. The profile comes from the single largest Tetonka component. Full methodology.