SinkholeOdds

Sinkhole risk in Boone County, IN: 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
18%
At or near the surface
0%
Buried under cover
18%

What this means before you buy

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

That works out to roughly 77 of Boone County's 423 square miles on soluble rock. With about 78,773 residents (186 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 400 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: why gypsum and salt move faster than limestone, and why the 18% under cover still counts.

Counties around Boone County

The nearest county rated sinkhole country is Monroe County, IN, about 62 miles south. 5 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 Muscatatuck Group (limestone), Devonian in age, covering about 17% of the county. Next is the Wabash Formation at 2%.

The county also lies over the Illinois 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 Indiana

Boone County ranks 39 of 92 in Indiana for soluble rock at the surface, and sits above 0% of US counties on that measure.