Sinkhole risk in Leelanau 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: 42%
At or near the surface: 7%
Buried under cover: 34%

What this means before you buy

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

That works out to roughly 144 of Leelanau County's 347 square miles on soluble rock, 26 of them with the rock at or near the surface. With about 22,871 residents (66 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 511 map points about 0.8 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 34% under cover still counts.

Counties around Leelanau County

The nearest county rated sinkhole country is Emmet County, MI, about 60 miles northeast. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Benzie County, MI 36 mi south · 0% at surface
Grand Traverse County, MI 38 mi southeast · 0% at surface
Charlevoix County, MI 41 mi northeast · 11% at surface
Antrim County, MI 44 mi east · 0% at surface
Door County, WI 49 mi west · under 1% at surface
Kalkaska County, MI 57 mi southeast · 0% at surface

What Leelanau County is built on

The largest mapped soluble unit here is the Traverse Group (limestone), Middle Devonian in age, covering about 42% 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

Leelanau County ranks 2 of 83 in Michigan for soluble rock at the surface, and sits above 66% of US counties on that measure.