SinkholeOdds

Sinkhole risk in Eaton 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
20%
At or near the surface
0%
Buried under cover
20%

What to do about a house in Eaton County

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

That works out to roughly 116 of Eaton County's 575 square miles on soluble rock. With about 109,494 residents (190 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 391 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 20% under cover still counts.

Counties around Eaton County

The nearest county rated sinkhole country is Barry County, MI, about 24 miles west, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

What Eaton County is built on

The largest mapped soluble unit here is the Michigan Formation (black shale), Mississippian in age, covering about 13% of the county. Next is the Bayport Limestone at 8%.

13% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

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

Eaton County ranks 31 of 83 in Michigan for soluble rock at the surface, and sits above 0% of US counties on that measure.