SinkholeOdds

Sinkhole risk in Sullivan County, MO: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock
4%
At or near the surface
0%
Buried under cover
4%

The next step for one property

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 26 of Sullivan County's 648 square miles on soluble rock. With about 5,750 residents (9 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 402 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Sullivan County

The nearest county rated sinkhole country is Cooper County, MO, about 95 miles south. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Kansas City Group (limestone), Late Pennsylvanian-Upper Series-Missourian Stage in age, covering about 4% of the county.

The county also lies over the Forest City Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Missouri

Sullivan County ranks 114 of 115 in Missouri for soluble rock at the surface, and sits above 0% of US counties on that measure.