SinkholeOdds

Sinkhole risk in Otsego County, MI: 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
9%
At or near the surface
0%
Buried under cover
9%

What to do about a house in Otsego County

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

That works out to roughly 47 of Otsego County's 515 square miles on soluble rock. With about 26,083 residents (51 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 384 map points about 1.2 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 9% under cover still counts.

Counties around Otsego County

The nearest county rated sinkhole country is Crawford County, MI, about 24 miles south, close enough that the same rock may run under the county line. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Which formation it is

The largest mapped soluble unit here is the Bedford Shale (shale), Upper Devonian in age, covering about 9% 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 Michigan

Otsego County ranks 72 of 83 in Michigan for soluble rock at the surface, and sits above 0% of US counties on that measure.