Sinkhole risk in Grundy County, MO: 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: 8%
At or near the surface: 0%
Buried under cover: 8%

What to do about a house in Grundy County

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

That works out to roughly 37 of Grundy County's 435 square miles on soluble rock. With about 9,766 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 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Grundy County

The nearest county rated sinkhole country is Jackson County, MO, about 87 miles southwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Mercer County, MO 21 mi north · 0% at surface
Livingston County, MO 23 mi south · 0% at surface
Daviess County, MO 24 mi southwest · 0% at surface
Sullivan County, MO 25 mi east · 0% at surface
Harrison County, MO 28 mi northwest · 0% at surface
Linn County, MO 30 mi southeast · 0% at surface

What Grundy County is built on

The largest mapped soluble unit here is the Kansas City Group (limestone), Late Pennsylvanian-Upper Series-Missourian Stage in age, covering about 8% of the county.

The county also lies over the Forest City 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 Missouri

Grundy County ranks 91 of 115 in Missouri for soluble rock at the surface, and sits above 0% of US counties on that measure.