Sinkhole risk in Mahoning 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: 27%
At or near the surface: 0%
Buried under cover: 27%

What to do about a house in Mahoning County

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

That works out to roughly 110 of Mahoning County's 412 square miles on soluble rock. With about 225,786 residents (549 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 352 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and why the 27% under cover still counts.

Counties around Mahoning County

The nearest county rated sinkhole country is Monroe County, MI, about 154 miles northwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Columbiana County, OH 17 mi south · 0% at surface
Trumbull County, OH 20 mi north · 0% at surface
Lawrence County, PA 23 mi east · 6% at surface
Portage County, OH 25 mi northwest · 0% at surface
Beaver County, PA 31 mi southeast · 9% at surface
Mercer County, PA 34 mi northeast · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Allegheny and Pottsville Groups, Undivided (shale), Pennsylvanian in age, covering about 27% of the county.

The county also lies over the Michigan Basin; Ohio Basin; Appalachian 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 Ohio

Mahoning County ranks 52 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.