SinkholeOdds

Sinkhole risk in Cheboygan 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
75%
At or near the surface
1%
Buried under cover
74%

The next step for one property

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

That works out to roughly 536 of Cheboygan County's 715 square miles on soluble rock, 9 of them with the rock at or near the surface. With about 25,964 residents (36 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 324 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: why gypsum and salt move faster than limestone, and why the 74% under cover still counts.

Counties around Cheboygan County

The nearest county rated sinkhole country is Emmet County, MI, about 25 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 Cheboygan County is built on

The largest mapped soluble unit here is the Traverse Group (limestone), Middle Devonian in age, covering about 41% of the county. Next is the Detroit River Group at 25%.

25% 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

Cheboygan County ranks 3 of 83 in Michigan for soluble rock at the surface, and sits above 56% of US counties on that measure.