Sinkhole risk in Wright County, MO: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 100%
At or near the surface: 100%
Buried under cover: 0%

What to do about a house in Wright County

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 682 of Wright County's 682 square miles on soluble rock, 682 of them with the rock at or near the surface. With about 19,505 residents (29 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 380 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Wright County

The closest county with no soluble rock mapped is Van Buren County, AR, about 116 miles south. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Webster County, MO 22 mi west · 100% at surface
Douglas County, MO 22 mi south · 100% at surface
Laclede County, MO 28 mi north · 100% at surface
Texas County, MO 29 mi east · 100% at surface
Pulaski County, MO 41 mi north · 100% at surface
Dallas County, MO 42 mi northwest · 100% at surface

What Wright County is built on

The largest mapped soluble unit here is the Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (dolostone (dolomite)), Early Ordovician-Ibexian Series in age, covering about 85% of the county. Next is the Roubidoux Formation at 13%.

Against the rest of Missouri

Wright County ranks 20 of 115 in Missouri for soluble rock at the surface, and sits above 99% of US counties on that measure.