Soil series profile
Neldore soil series
Neldore is a well drained soil with a silty clay surface, mapped on 1,266,627 acres in 36 counties across 2 states. Hydrologic group D.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- D 100% of mapped acres
- Typical topsoil pH
- 6.7 neutral · range 6.7–7.0
- Mapped area
- 1.3M acres in 36 counties, 2 states
Typical Neldore profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–3 in (A) | Silty clay | 6.7 | 45% | 7% | 1.5% |
| 3–9 in (C1) | Silty clay | 6.7 | 50% | 5% | 0.75% |
| 9–15 in (C2) | Silty clay | 6.7 | 50% | 5% | 0.25% |
| 15–60 in (Cr) | Bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Neldore soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Neldore soils is neutral: pH 6.7 (most land between 6.7 and 7.0), the range most vegetables, flowers and lawn grasses prefer.
Clayey topsoil covers 99% of mapped Neldore 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 (52% of mapped Neldore acres).
100% of mapped Neldore acres is moderately well to excessively drained, which suits most garden plants.
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.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Neldore 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 Neldore soil is found
Mapped acres
Neldore is mapped in Montana and Wyoming.
| County | Acres | Share of county land |
|---|---|---|
| Phillips County, MT | 225,974 | 6.1% |
| Petroleum County, MT | 157,997 | 14.9% |
| Rosebud County, MT | 150,773 | 3.1% |
| Fergus County, MT | 139,788 | 5.1% |
| Carter County, MT | 118,741 | 6.2% |
| Garfield County, MT | 109,783 | 3.8% |
| Valley County, MT | 82,178 | 2.5% |
| Chouteau County, MT | 60,084 | 2.4% |
| Fallon County, MT | 47,011 | 4.6% |
| Musselshell County, MT | 39,842 | 3.4% |
| Toole County, MT | 22,017 | 2.0% |
| Blaine County, MT | 16,294 | 0.6% |
| Natrona County, WY | 14,443 | 0.4% |
| Prairie County, MT | 13,467 | 1.2% |
| Dawson County, MT | 12,432 | 0.8% |
| McCone County, MT | 11,190 | 0.7% |
| Golden Valley County, MT | 11,075 | 1.5% |
| Pondera County, MT | 8,685 | 0.8% |
| Custer County, MT | 8,630 | 0.3% |
| Teton County, MT | 4,655 | 0.3% |
| Hill County, MT | 3,862 | 0.2% |
| Judith Basin County, MT | 1,496 | 0.2% |
| Roosevelt County, MT | 1,418 | 0.1% |
| Big Horn County, MT | 1,287 | 0.0% |
| Hot Springs County, WY | 620 | 0.1% |
| Park County, WY | 499 | 0.0% |
| Carbon County, WY | 434 | 0.0% |
| Liberty County, MT | 357 | 0.0% |
| Wheatland County, MT | 314 | 0.0% |
| Cascade County, MT | 288 | 0.0% |
| Powder River County, MT | 195 | 0.0% |
| Glacier County, MT | 195 | 0.0% |
| Broadwater County, MT | 164 | 0.0% |
| Stillwater County, MT | 26 | 0.0% |
| Treasure County, MT | 11 | 0.0% |
| Yellowstone County, MT | 5 | 0.0% |
Septic absorption fields
NRCS rating, share of Neldore 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 Neldore 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 10–38% (median 22%).
- 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 | 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 | 0.0% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 100.0% |
| 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 Neldore (component kind "Series") in SSURGO: 1,266,627 acres.
- Method
- Shares are by mapped acres of Neldore components. The profile comes from the single largest Neldore component. Full methodology.