Sinkhole risk in Carter County, MO: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 100%
At or near the surface: 100%
Buried under cover: 0%

What to do about a house in Carter County

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 506 of Carter County's 507 square miles on soluble rock, 506 of them with the rock at or near the surface. With about 5,359 residents (11 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 337 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Carter County

The closest county with no soluble rock mapped is Clay County, AR, about 49 miles southeast. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Ripley County, MO 21 mi south · 95% at surface
Shannon County, MO 28 mi northwest · 99% at surface
Reynolds County, MO 29 mi north · 98% at surface
Wayne County, MO 29 mi northeast · 95% at surface
Oregon County, MO 31 mi southwest · 100% at surface
Butler County, MO 34 mi southeast · 44% at surface

What Carter County is built on

The largest mapped soluble unit here is the Roubidoux Formation (sandstone), Early Ordovician-Ibexian Series in age, covering about 52% of the county. Next is the Gasconade Dolomite at 42%.

Against the rest of Missouri

Carter County ranks 21 of 115 in Missouri for soluble rock at the surface, and sits above 99% of US counties on that measure.