Soil series profile
Tillman soil series
Tillman is a well drained soil with a clay loam surface, mapped on 1,134,090 acres in 31 counties across 2 states. Hydrologic group C.
- Drainage class
- Well drained >99% of mapped acres
- Hydrologic group
- C 93% of mapped acres
- Typical topsoil pH
- 7.0 neutral · range 7.0–7.5
- Mapped area
- 1.1M acres in 31 counties, 2 states
Typical Tillman profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–7 in (Ap) | Clay loam | 7.0 | 28% | 22% | 2% |
| 7–22 in (Bt) | Clay loam | 7.5 | 38% | 31% | 1.5% |
| 22–62 in (Btk) | Clay | 8.2 | 42% | 23% | 0.3% |
| 62–80 in (2BC) | Clay | 8.2 | 40% | 22% | 0.3% |
What this means
What Tillman soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Tillman soils is neutral: pH 7.0 (most land between 7.0 and 7.5), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 94% of mapped Tillman acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is clay loam (75% of mapped Tillman acres).
>99% of mapped Tillman acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 94% 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 94% of the acres in mapped Tillman soils very limited, 0% somewhat limited and 0% not limited (6% not rated, such as urban land, pits or water).
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 Tillman soil is found
Mapped acres
Tillman is mapped in Texas and Oklahoma.
| County | Acres | Share of county land |
|---|---|---|
| Kiowa County, OK | 91,975 | 14.2% |
| Wilbarger County, TX | 91,578 | 15.1% |
| Haskell County, TX | 78,289 | 13.5% |
| Foard County, TX | 72,446 | 13.2% |
| Jones County, TX | 67,278 | 11.3% |
| Baylor County, TX | 64,191 | 11.4% |
| Stonewall County, TX | 63,686 | 10.8% |
| Hardeman County, TX | 60,434 | 13.6% |
| Tillman County, OK | 49,399 | 8.7% |
| Archer County, TX | 47,855 | 8.2% |
| Cottle County, TX | 45,020 | 7.8% |
| Cotton County, OK | 44,625 | 10.9% |
| Comanche County, OK | 44,057 | 6.5% |
| Wichita County, TX | 41,880 | 10.8% |
| Jackson County, OK | 34,334 | 6.7% |
| Caddo County, OK | 32,442 | 4.0% |
| Knox County, TX | 32,070 | 5.9% |
| Fisher County, TX | 31,685 | 5.5% |
| Taylor County, TX | 30,390 | 5.2% |
| Childress County, TX | 25,451 | 5.6% |
| Major County, OK | 24,147 | 4.0% |
| Woods County, OK | 21,809 | 2.7% |
| Young County, TX | 15,149 | 2.6% |
| Throckmorton County, TX | 7,103 | 1.2% |
| Greer County, OK | 7,012 | 1.7% |
| Beckham County, OK | 4,365 | 0.8% |
| Dickens County, TX | 3,339 | 0.6% |
| Nolan County, TX | 1,183 | 0.2% |
| Clay County, TX | 436 | 0.1% |
| Runnels County, TX | 243 | 0.0% |
| Harmon County, OK | 222 | 0.1% |
Septic absorption fields
NRCS rating, share of Tillman acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 93.6% |
| Not rated | 6.4% |
Drainage, water table and flooding
Share of Tillman acres
- Depth to seasonal high water table
- None reported within about 6.5 feet (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 1–2% (median 2%).
- Topsoil organic matter
- Median 2%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 99.9% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| 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 | 93.4% |
| D: very slow infiltration (clayey, shallow or wet) | 0.2% |
| 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 | 0.0% |
| Not rated | 6.4% |
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 Tillman (component kind "Series") in SSURGO: 1,134,090 acres.
- Method
- Shares are by mapped acres of Tillman components. The profile comes from the single largest Tillman component. Full methodology.