Soil series profile
Amor soil series
Amor is a well drained soil with a loam surface, mapped on 1,025,487 acres in 48 counties across 4 states. Hydrologic group C.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- C 99% of mapped acres
- Typical topsoil pH
- 6.5 slightly acidic · range 6.5–7.0
- Mapped area
- 1.0M acres in 48 counties, 4 states
Typical Amor profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–6 in (Ap) | Loam | 6.5 | 22% | 41% | 3% |
| 6–13 in (Bw1) | Loam | 7.1 | 22% | 47% | 2% |
| 13–19 in (Bw2) | Loam | 7.3 | 21% | 47% | 1.5% |
| 19–31 in (Bk) | Loam | 8.1 | 24% | 28% | 0.8% |
| 31–79 in (Cr) | Bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Amor soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Amor soils is slightly acidic: pH 6.5 (most land between 6.5 and 7.0), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Amor acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (>99% of mapped Amor acres).
100% of mapped Amor acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 99% 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 Amor 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 Amor soil is found
Mapped acres
Amor is mapped in North Dakota, South Dakota, Montana and Wyoming.
| County | Acres | Share of county land |
|---|---|---|
| Grant County, ND | 127,202 | 12.0% |
| Stark County, ND | 101,611 | 11.9% |
| Emmons County, ND | 83,317 | 8.7% |
| Morton County, ND | 81,383 | 6.6% |
| Harding County, SD | 76,372 | 4.5% |
| Perkins County, SD | 59,268 | 3.2% |
| Dunn County, ND | 56,561 | 4.4% |
| Hettinger County, ND | 53,908 | 7.4% |
| Bowman County, ND | 45,174 | 6.1% |
| Adams County, ND | 43,195 | 6.8% |
| Sioux County, ND | 39,317 | 5.6% |
| Mercer County, ND | 32,599 | 4.9% |
| Williams County, ND | 25,348 | 1.9% |
| McKenzie County, ND | 24,140 | 1.4% |
| Oliver County, ND | 24,061 | 5.2% |
| Fergus County, MT | 14,604 | 0.5% |
| Slope County, ND | 14,279 | 1.8% |
| Teton County, MT | 14,126 | 1.0% |
| Logan County, ND | 13,546 | 2.2% |
| Billings County, ND | 11,322 | 1.5% |
| Corson County, SD | 11,026 | 0.7% |
| Uinta County, WY | 10,776 | 0.8% |
| Ziebach County, SD | 10,183 | 0.8% |
| McLean County, ND | 9,115 | 0.7% |
| Burleigh County, ND | 7,259 | 0.7% |
| McIntosh County, ND | 6,225 | 1.0% |
| Golden Valley County, ND | 5,422 | 0.8% |
| Chouteau County, MT | 4,418 | 0.2% |
| Wheatland County, MT | 4,310 | 0.5% |
| Sweet Grass County, MT | 4,210 | 0.3% |
| Pondera County, MT | 3,759 | 0.4% |
| Richland County, MT | 1,702 | 0.1% |
| Dewey County, SD | 1,320 | 0.1% |
| Mountrail County, ND | 1,064 | 0.1% |
| Roosevelt County, MT | 815 | 0.1% |
| Daniels County, MT | 730 | 0.1% |
| Wibaux County, MT | 556 | 0.1% |
| Meagher County, MT | 367 | 0.0% |
| Lincoln County, WY | 336 | 0.0% |
| Sheridan County, MT | 201 | 0.0% |
| Fallon County, MT | 142 | 0.0% |
| McCone County, MT | 80 | 0.0% |
| Stillwater County, MT | 67 | 0.0% |
| Campbell County, SD | 57 | 0.0% |
| Dawson County, MT | 10 | 0.0% |
| Walworth County, SD | 2 | 0.0% |
| Park County, MT | 2 | 0.0% |
| Judith Basin County, MT | 0 | 0.0% |
Septic absorption fields
NRCS rating, share of Amor 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 Amor acres
- Depth to seasonal high water table
- About 4.3 feet (51 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 5–20% (median 8%).
- Topsoil organic matter
- Median 3%.
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 | 1.1% |
| C: slow infiltration | 98.9% |
| 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 Amor (component kind "Series") in SSURGO: 1,025,487 acres.
- Method
- Shares are by mapped acres of Amor components. The profile comes from the single largest Amor component. Full methodology.