Sinkhole risk in Cape Girardeau County, MO: Sinkhole country

Sinkhole country

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

On soluble rock: 85%
At or near the surface: 81%
Buried under cover: 3%

The next step for one property

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

That works out to roughly 489 of Cape Girardeau County's 579 square miles on soluble rock, 471 of them with the rock at or near the surface. With about 83,658 residents (145 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 296 map points about 1.4 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Cape Girardeau County

The closest county with no soluble rock mapped is Ballard County, KY, about 44 miles southeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Bollinger County, MO 19 mi west · 91% at surface
Alexander County, IL 23 mi southeast · 31% at surface
Perry County, MO 23 mi north · 86% at surface
Scott County, MO 24 mi south · 8% at surface
Union County, IL 25 mi east · 53% at surface
Jackson County, IL 32 mi northeast · under 1% at surface

What Cape Girardeau County is built on

The largest mapped soluble unit here is the St. Peter Sandstone, Everton Formation (dolostone (dolomite)), Middle Ordovician to Early Ordovician in age, covering about 17% of the county. Next is the Decorah Group, Plattin Group at 16%.

Against the rest of Missouri

Cape Girardeau County ranks 45 of 115 in Missouri for soluble rock at the surface, and sits above 95% of US counties on that measure.