Sinkhole risk in Hickory 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: 92%
Buried under cover: 0%

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 367 of Hickory County's 399 square miles on soluble rock, 367 of them with the rock at or near the surface. With about 8,766 residents (22 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 320 map points about 1.1 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 Hickory County

The closest county with no soluble rock mapped is Johnson County, AR, about 163 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Polk County, MO 23 mi south · 97% at surface
Dallas County, MO 24 mi southeast · 100% at surface
Benton County, MO 25 mi north · 89% at surface
St. Clair County, MO 26 mi west · 43% at surface
Camden County, MO 31 mi east · 100% at surface
Cedar County, MO 32 mi southwest · 54% 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 Osagean Series at 25%.

Against the rest of Missouri

Hickory County ranks 39 of 115 in Missouri for soluble rock at the surface, and sits above 97% of US counties on that measure.