Sinkhole risk in Pulaski 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%

The next step for one property

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

That works out to roughly 547 of Pulaski County's 547 square miles on soluble rock, 547 of them with the rock at or near the surface. With about 53,964 residents (99 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 355 map points about 1.2 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 Pulaski County

The closest county with no soluble rock mapped is Clay County, AR, about 141 miles southeast. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Phelps County, MO 23 mi east · 100% at surface
Laclede County, MO 24 mi southwest · 100% at surface
Maries County, MO 28 mi northeast · 100% at surface
Miller County, MO 30 mi northwest · 100% at surface
Camden County, MO 33 mi northwest · 100% at surface
Texas County, MO 38 mi south · 100% at surface

The rock underneath

The largest mapped soluble unit here is the Roubidoux Formation (sandstone), Early Ordovician-Ibexian Series in age, covering about 43% of the county. Next is the Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite at 29%.

Against the rest of Missouri

Pulaski County ranks 15 of 115 in Missouri for soluble rock at the surface, and sits above 99% of US counties on that measure.