Soil series profile
Williams soil series
Williams is a well drained soil with a loam surface, mapped on 4,235,589 acres in 48 counties across 3 states. Hydrologic group B.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- B 61% of mapped acres
- Typical topsoil pH
- 7.2 neutral · range 7.0–7.2
- Mapped area
- 4.2M acres in 48 counties, 3 states
Typical Williams profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–6 in (Ap) | Loam | 7.0 | 22% | 41% | 3.5% |
| 6–10 in (Bt1) | Clay loam | 7.1 | 31% | 35% | 2% |
| 10–16 in (Bt2) | Clay loam | 7.2 | 31% | 35% | 1.5% |
| 16–22 in (Btk) | Clay loam | 8.0 | 31% | 35% | 1% |
| 22–36 in (Bk) | Clay loam | 8.3 | 29% | 34% | 1% |
| 36–59 in (BCk) | Loam | 8.6 | 26% | 38% | 0.5% |
| 59–79 in (C) | Loam | 8.6 | 26% | 38% | 0.5% |
What this means
What Williams soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Williams soils is neutral: pH 7.2 (most land between 7.0 and 7.2), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Williams acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (97% of mapped Williams acres).
100% of mapped Williams acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.
For a septic system
For conventional septic absorption fields, NRCS rates 39% of the acres in mapped Williams soils very limited, 61% somewhat limited and 0% not limited.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Williams soil is found
Mapped acres
Williams is mapped in North Dakota, Montana and South Dakota.
| County | Acres | Share of county land |
|---|---|---|
| McLean County, ND | 366,399 | 27.3% |
| Williams County, ND | 358,776 | 27.0% |
| Mountrail County, ND | 287,204 | 24.4% |
| Sheridan County, MT | 285,741 | 26.9% |
| Faulk County, SD | 194,678 | 30.3% |
| Burleigh County, ND | 194,040 | 18.7% |
| Edmunds County, SD | 191,271 | 26.1% |
| Divide County, ND | 185,330 | 22.5% |
| McPherson County, SD | 177,001 | 24.4% |
| Richland County, MT | 143,648 | 10.5% |
| Burke County, ND | 135,714 | 19.0% |
| Ward County, ND | 132,827 | 10.2% |
| Stutsman County, ND | 129,992 | 9.2% |
| Glacier County, MT | 119,496 | 7.6% |
| Logan County, ND | 117,386 | 18.9% |
| Sheridan County, ND | 101,863 | 16.3% |
| Roosevelt County, MT | 100,799 | 6.7% |
| Kidder County, ND | 92,778 | 10.9% |
| McIntosh County, ND | 87,557 | 14.5% |
| Emmons County, ND | 85,784 | 9.0% |
| Campbell County, SD | 80,710 | 17.1% |
| Wells County, ND | 58,576 | 7.2% |
| McKenzie County, ND | 55,319 | 3.1% |
| Valley County, MT | 54,214 | 1.7% |
| Daniels County, MT | 53,426 | 5.9% |
| Mercer County, ND | 52,925 | 8.0% |
| Toole County, MT | 43,445 | 4.0% |
| McCone County, MT | 42,503 | 2.5% |
| Blaine County, MT | 39,218 | 1.4% |
| Oliver County, ND | 37,477 | 8.1% |
| Brown County, SD | 32,711 | 3.0% |
| LaMoure County, ND | 32,001 | 4.4% |
| Dunn County, ND | 29,569 | 2.3% |
| Potter County, SD | 27,106 | 4.9% |
| Dickey County, ND | 22,925 | 3.2% |
| Walworth County, SD | 22,767 | 5.1% |
| Spink County, SD | 15,489 | 1.6% |
| Morton County, ND | 13,675 | 1.1% |
| Dawson County, MT | 10,567 | 0.7% |
| Chouteau County, MT | 6,154 | 0.2% |
| Liberty County, MT | 5,458 | 0.6% |
| McHenry County, ND | 3,014 | 0.2% |
| Pondera County, MT | 2,958 | 0.3% |
| Hill County, MT | 2,862 | 0.2% |
| Wibaux County, MT | 1,274 | 0.2% |
| Foster County, ND | 627 | 0.2% |
| Phillips County, MT | 335 | 0.0% |
| Grant County, ND | 0 | 0.0% |
Septic absorption fields
NRCS rating, share of Williams acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 61.2% |
| Very limited | 38.8% |
Drainage, water table and flooding
Share of Williams 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 2–10% (median 4%).
- Topsoil organic matter
- Median 4%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| 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 | 61.2% |
| C: slow infiltration | 38.8% |
| D: very slow infiltration (clayey, shallow or wet) | 0.0% |
| 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% |
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 Williams (component kind "Series") in SSURGO: 4,235,589 acres.
- Method
- Shares are by mapped acres of Williams components. The profile comes from the single largest Williams component. Full methodology.