Sinkhole risk in Crawford 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: 31%
At or near the surface: 0%
Buried under cover: 31%

What to do about a house in Crawford County

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

That works out to roughly 123 of Crawford County's 402 square miles on soluble rock. With about 41,626 residents (104 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 385 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 31% under cover still counts, and how these percentages are measured.

Counties around Crawford County

The nearest county rated sinkhole country is Monroe County, MI, about 79 miles north. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Wyandot County, OH 20 mi west · 0% at surface
Richland County, OH 21 mi east · 0% at surface
Seneca County, OH 22 mi northwest · 0% at surface
Marion County, OH 22 mi southwest · 0% at surface
Morrow County, OH 23 mi south · 0% at surface
Huron County, OH 27 mi northeast · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Columbus Limestone (limestone), Devonian in age, covering about 15% of the county. Next is the Olentangy Shale at 8%.

Against the rest of Ohio

Crawford County ranks 24 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.