Sinkhole risk in Pawnee County, KS: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 19%
At or near the surface: 19%
Buried under cover: 0%

What this means before you buy

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 146 of Pawnee County's 754 square miles on soluble rock, 146 of them with the rock at or near the surface. With about 6,012 residents (8 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 331 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Pawnee County

The nearest county rated sinkhole country is Comanche County, KS, about 69 miles south. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Edwards County, KS 21 mi south · 2% at surface
Rush County, KS 24 mi north · 55% at surface
Stafford County, KS 30 mi east · 0% at surface
Barton County, KS 33 mi northeast · 37% at surface
Hodgeman County, KS 37 mi west · 42% at surface
Ness County, KS 42 mi northwest · 56% at surface

What Pawnee County is built on

The largest mapped soluble unit here is the Greenhorn Limestone and Graneros Shale (limestone), Late Cretaceous in age, covering about 15% of the county. Next is the Carlile Shale at 5%.

The county also lies over the Permian Basin, Anadarko Basin,Dalhart Basin, Palo Duro 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 Kansas

Pawnee County ranks 58 of 105 in Kansas for soluble rock at the surface, and sits above 74% of US counties on that measure.