Sinkhole risk in Randolph 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: 100%
At or near the surface: 0%
Buried under cover: 100%

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 452 of Randolph County's 452 square miles on soluble rock. With about 24,337 residents (54 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 391 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 100% under cover still counts, and how these percentages are measured.

Counties around Randolph County

The nearest county rated sinkhole country is Kenton County, KY, about 89 miles south. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Jay County, IN 19 mi north · 0% at surface
Darke County, OH 20 mi east · 0% at surface
Wayne County, IN 21 mi south · under 1% at surface
Delaware County, IN 21 mi west · 0% at surface
Henry County, IN 26 mi southwest · 0% at surface
Blackford County, IN 27 mi northwest · 0% at surface

What Randolph County is built on

The largest mapped soluble unit here is the Louisville Limestone through Brassfield Limestone (limestone), Silurian in age, covering about 88% of the county. Next is the Ordovician rocks, undifferentiated at 6%.

Against the rest of Indiana

Randolph County ranks 75 of 92 in Indiana for soluble rock at the surface, and sits above 0% of US counties on that measure.