Soil series profile
Forkwood soil series
Forkwood is a well drained soil with a loam surface, mapped on 568,441 acres in 15 counties across 2 states. Hydrologic group B.
- Drainage class
- Well drained >99% of mapped acres
- Hydrologic group
- B 97% of mapped acres
- Typical topsoil pH
- 7.2 neutral · range 7.0–7.5
- Mapped area
- 568k acres in 15 counties, 2 states
Typical Forkwood profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–2 in (A) | Loam | 7.0 | 20% | 40% | 1.5% |
| 2–23 in (Bt) | Clay loam | 7.8 | 32% | 35% | 0.75% |
| 23–79 in (Bk) | Loam | 8.4 | 25% | 35% | 0.25% |
What this means
What Forkwood soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Forkwood soils is neutral: pH 7.2 (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 97% of mapped Forkwood acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (70% of mapped Forkwood acres).
>99% of mapped Forkwood 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 3% of the acres in mapped Forkwood soils very limited, 95% somewhat limited and 2% not limited.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Forkwood soil is found
Mapped acres
Forkwood is mapped in Wyoming and Montana.
| County | Acres | Share of county land |
|---|---|---|
| Campbell County, WY | 144,444 | 4.7% |
| Converse County, WY | 86,164 | 3.5% |
| Natrona County, WY | 83,710 | 2.5% |
| Weston County, WY | 74,075 | 4.8% |
| Washakie County, WY | 47,607 | 3.3% |
| Johnson County, WY | 46,104 | 1.8% |
| Niobrara County, WY | 39,328 | 2.3% |
| Sheridan County, WY | 17,064 | 1.1% |
| Park County, WY | 11,650 | 0.7% |
| Platte County, WY | 11,220 | 0.9% |
| Hot Springs County, WY | 6,909 | 0.7% |
| Crook County, WY | 118 | 0.0% |
| Powder River County, MT | 30 | 0.0% |
| Big Horn County, WY | 10 | 0.0% |
| Goshen County, WY | 7 | 0.0% |
Septic absorption fields
NRCS rating, share of Forkwood acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 1.6% |
| Somewhat limited | 95.4% |
| Very limited | 2.7% |
| Not rated | 0.3% |
Drainage, water table and flooding
Share of Forkwood acres
- Depth to seasonal high water table
- About 3.1 feet (37 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 3–9% (median 3%).
- 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 | 99.6% |
| Moderately well drained | 0.1% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 0.2% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 96.8% |
| C: slow infiltration | 2.9% |
| D: very slow infiltration (clayey, shallow or wet) | 0.1% |
| 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 | 0.3% |
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 Forkwood (component kind "Series") in SSURGO: 568,441 acres.
- Method
- Shares are by mapped acres of Forkwood components. The profile comes from the single largest Forkwood component. Full methodology.