Sinkhole risk in Audrain County, MO: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 69%
At or near the surface: 0%
Buried under cover: 69%

What to do about a house in Audrain County

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 480 of Audrain County's 692 square miles on soluble rock. With about 24,304 residents (35 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 293 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 69% under cover still counts, and the signs to look for and how an inspection works.

Counties around Audrain County

The nearest county rated sinkhole country is Osage County, MO, about 52 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Monroe County, MO 21 mi northwest · 7% at surface
Callaway County, MO 27 mi south · 28% at surface
Montgomery County, MO 28 mi southeast · 30% at surface
Ralls County, MO 29 mi northeast · 4% at surface
Boone County, MO 29 mi southwest · 27% at surface
Pike County, MO 37 mi east · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Marmaton Group (limestone), Middle Pennsylvanian-Middle Series-Desmonian Stage in age, covering about 58% of the county. Next is the Osagean Series at 12%.

Against the rest of Missouri

Audrain County ranks 79 of 115 in Missouri for soluble rock at the surface, and sits above 0% of US counties on that measure.