Sinkhole risk in Miller 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 593 of Miller County's 593 square miles on soluble rock, 593 of them with the rock at or near the surface. With about 25,668 residents (43 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 304 map points about 1.4 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 Miller County

The closest county with no soluble rock mapped is Macoupin County, IL, about 153 miles northeast. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Cole County, MO 21 mi north · 94% at surface
Camden County, MO 22 mi southwest · 100% at surface
Maries County, MO 28 mi east · 100% at surface
Morgan County, MO 28 mi northwest · 100% at surface
Pulaski County, MO 30 mi southeast · 100% at surface
Moniteau County, MO 30 mi north · 95% at surface

What Miller County is built on

The largest mapped soluble unit here is the Roubidoux Formation (sandstone), Early Ordovician-Ibexian Series in age, covering about 41% of the county. Next is the Gasconade Dolomite at 32%.

Against the rest of Missouri

Miller County ranks 10 of 115 in Missouri for soluble rock at the surface, and sits above 99% of US counties on that measure.