Sinkhole risk in Mercer County, OH: 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: 3%
Buried under cover: 97%

What to do about a house in Mercer County

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

That works out to roughly 462 of Mercer County's 462 square miles on soluble rock, 13 of them with the rock at or near the surface. With about 42,648 residents (92 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 380 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Mercer County

The nearest county rated sinkhole country is Kenton County, KY, about 111 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Jay County, IN 21 mi west · 0% at surface
Auglaize County, OH 21 mi east · 1% at surface
Adams County, IN 22 mi northwest · 0% at surface
Van Wert County, OH 22 mi north · 0% at surface
Shelby County, OH 26 mi southeast · 0% at surface
Darke County, OH 28 mi south · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Lockport Dolomite (dolostone (dolomite)), Silurian in age, covering about 48% of the county. Next is the Salina Group at 41%.

Against the rest of Ohio

Mercer County ranks 6 of 88 in Ohio for soluble rock at the surface, and sits above 60% of US counties on that measure.