Sinkhole risk in Dent 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 this means before you buy

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

That works out to roughly 753 of Dent County's 753 square miles on soluble rock, 753 of them with the rock at or near the surface. With about 14,721 residents (20 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 326 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Dent County

The closest county with no soluble rock mapped is Clay County, AR, about 104 miles southeast. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Phelps County, MO 25 mi northwest · 100% at surface
Crawford County, MO 27 mi north · 100% at surface
Shannon County, MO 32 mi south · 99% at surface
Reynolds County, MO 33 mi southeast · 98% at surface
Texas County, MO 33 mi southwest · 100% at surface
Washington County, MO 40 mi northeast · 96% at surface

Which formation it is

The largest mapped soluble unit here is the Gasconade Dolomite (dolostone (dolomite)), Early Ordovician-Ibexian Series in age, covering about 49% of the county. Next is the Roubidoux Formation at 44%.

Against the rest of Missouri

Dent County ranks 4 of 115 in Missouri for soluble rock at the surface, and sits above 99% of US counties on that measure.