SinkholeOdds

Sinkhole risk in Ralls 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
82%
At or near the surface
4%
Buried under cover
78%

The next step for one property

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 384 of Ralls County's 470 square miles on soluble rock, 18 of them with the rock at or near the surface. With about 10,499 residents (22 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 285 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 78% under cover still counts, and the signs to look for and how an inspection works.

Counties around Ralls County

The nearest county rated sinkhole country is Calhoun County, IL, about 53 miles southeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

The rock underneath

The largest mapped soluble unit here is the Osagean Series (limestone), Early Mississippian-Osagean Series in age, covering about 34% of the county. Next is the Kinderhookian Series at 24%.

Against the rest of Missouri

Ralls County ranks 74 of 115 in Missouri for soluble rock at the surface, and sits above 61% of US counties on that measure.