Sinkhole risk in Pike 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: 76%
At or near the surface: 0%
Buried under cover: 76%

What to do about a house in Pike 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 506 of Pike County's 670 square miles on soluble rock. With about 17,961 residents (27 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 552 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 76% under cover still counts, and the signs to look for and how an inspection works.

Counties around Pike County

The nearest county rated sinkhole country is Calhoun County, IL, about 30 miles southeast, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Lincoln County, MO 22 mi southeast · 0% at surface
Ralls County, MO 24 mi northwest · 4% at surface
Pike County, IL 25 mi northeast · 12% at surface
Calhoun County, IL 30 mi southeast · 51% at surface
Montgomery County, MO 32 mi southwest · 30% at surface
Audrain County, MO 37 mi west · 0% at surface

What Pike County is built on

The largest mapped soluble unit here is the Osagean Series (limestone), Early Mississippian-Osagean Series in age, covering about 27% of the county. Next is the Leemon Formation, Maquoketa Group, Cape Limestone, Kimmswick Limestone, Noix-Cyrene Limestone, Maquoketa Shale at 24%.

Against the rest of Missouri

Pike County ranks 106 of 115 in Missouri for soluble rock at the surface, and sits above 0% of US counties on that measure.