HomeSoil seriesCarnasaw
Carnasaw soil series
Carnasaw soils cover 1,773,351 mapped acres, mostly in Oklahoma and Arkansas. USDA rates shrink-swell a limit for houses without basements on 86% of that land, and a shallow water table a limit for basements on 0%.
It is the leading soil series by area in 12 of the counties and cities on this site, including Perry County, AR; Scott County, AR; Latimer County, OK.
SSURGO survey versions to August 5, 2026 · series description revised 2021-03
of its land: shrink-swell limits houses without basements
of its land: a shallow water table limits basements
median highest linear extensibility (6% and up is high)
median highest clay content in the top 150 cm
USDA's description
The Carnasaw series consists of deep, well drained, slowly permeable upland soils. These soils formed in residuum weathered from shale of Pennsylvanian age. These gently sloping to steep soils are on sideslopes of forested uplands of the Ouachita Mountains (MLRA 119) and the Arkansas Valley and Ridges (MLRA 118). Slopes are 1 to 60 percent.
Source: USDA NRCS series description (OSD) for Carnasaw, revised 2021-03. Read it.
Engineering properties
| Mapped area (SSURGO) | 1,773,351 acres |
| Shrink-swell limits houses without basements | 86.0% |
| Shallow water table limits basements | 0.0% |
| Very limited for septic absorption fields | 99.8% |
| Most common drainage class | Well drained |
| Most common hydrologic soil group | C |
| Taxonomic class | Fine, mixed, semiactive, thermic Typic Hapludults |
| Type location | McCurtain County, Oklahoma |
Where Carnasaw is mapped
| State | Mapped acres |
|---|---|
| Oklahoma | 892,291 |
| Arkansas | 881,060 |
Places where Carnasaw leads
Counties and cities where Carnasaw covers more mapped land than any other series.
| Place | Share of mapped land |
|---|---|
| Perry County, AR | 35% |
| Scott County, AR | 33% |
| Latimer County, OK | 31% |
| Saline County, AR | 29% |
| Garland County, AR | 22% |
| Le Flore County, OK | 22% |
| Atoka County, OK | 19% |
| Yell County, AR | 19% |
| Pushmataha County, OK | 19% |
| McCurtain County, OK | 16% |
| Pulaski County, AR | 14% |
| Haskell County, OK | 10% |
Other places where Carnasaw is a main soil
Counties and cities where Carnasaw is among the six soil series covering the most mapped land, but not the first. Share of the place's mapped land.
Counties
Sources
Shares and properties: USDA NRCS SSURGO via Soil Data Access, weighted by each component's share of its map units. Description: the USDA NRCS series description. How we count.