Sinkhole risk in Hancock County, OH: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 100%
At or near the surface: 0%
Buried under cover: 100%

What to do about a house in Hancock County

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 531 of Hancock County's 531 square miles on soluble rock. With about 75,016 residents (141 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 354 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 100% under cover still counts, and the signs to look for and how an inspection works.

Counties around Hancock County

The nearest county rated sinkhole country is Monroe County, MI, about 64 miles north. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Wyandot County, OH 21 mi southeast · 0% at surface
Hardin County, OH 23 mi south · 0% at surface
Putnam County, OH 24 mi west · 0% at surface
Wood County, OH 25 mi north · 0% at surface
Allen County, OH 28 mi southwest · 0% at surface
Seneca County, OH 29 mi east · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Salina Group (dolostone (dolomite)), Silurian in age, covering about 45% of the county. Next is the Tymochtee and Greenfield Formations, Undivided at 33%.

Against the rest of Ohio

Hancock County ranks 37 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.