Sinkhole risk in Wright County, IA: 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: 68%
At or near the surface: 0%
Buried under cover: 68%

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 394 of Wright County's 580 square miles on soluble rock. With about 12,729 residents (22 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 391 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 68% under cover still counts, and how these percentages are measured.

Counties around Wright County

The nearest county rated sinkhole country is Clayton County, IA, about 122 miles east. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Franklin County, IA 24 mi east · 0% at surface
Hancock County, IA 24 mi north · 0% at surface
Hamilton County, IA 24 mi south · 0% at surface
Humboldt County, IA 24 mi west · 0% at surface
Webster County, IA 31 mi southwest · 0% at surface
Cerro Gordo County, IA 34 mi northeast · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Kinderhook Series (limestone), Early Mississippian in age, covering about 46% of the county. Next is the Meramec Series at 22%.

Against the rest of Iowa

Wright County ranks 99 of 99 in Iowa for soluble rock at the surface, and sits above 0% of US counties on that measure.