Sinkhole risk in Bollinger County, MO: Sinkhole country

Sinkhole country

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

On soluble rock: 92%
At or near the surface: 91%
Buried under cover: under 1%

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 565 of Bollinger County's 618 square miles on soluble rock, 564 of them with the rock at or near the surface. With about 10,610 residents (17 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 331 map points about 1.4 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Bollinger County

The closest county with no soluble rock mapped is Mississippi County, MO, about 53 miles southeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Cape Girardeau County, MO 19 mi east · 81% at surface
Madison County, MO 21 mi northwest · 67% at surface
Wayne County, MO 28 mi southwest · 95% at surface
Perry County, MO 30 mi northeast · 86% at surface
Scott County, MO 31 mi southeast · 8% at surface
Stoddard County, MO 33 mi south · 3% at surface

The rock underneath

The largest mapped soluble unit here is the Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (dolostone (dolomite)), Early Ordovician-Ibexian Series in age, covering about 48% of the county. Next is the Roubidoux Formation at 26%.

Against the rest of Missouri

Bollinger County ranks 40 of 115 in Missouri for soluble rock at the surface, and sits above 97% of US counties on that measure.