Sinkhole risk in Trego 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: 57%
At or near the surface: 57%
Buried under cover: 0%

What to do about a house in Trego County

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 505 of Trego County's 889 square miles on soluble rock, 505 of them with the rock at or near the surface. With about 2,774 residents (3 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 410 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Trego County

The nearest county rated sinkhole country is Harlan County, NE, about 90 miles north. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Ellis County, KS 29 mi east · 39% at surface
Graham County, KS 30 mi north · 33% at surface
Ness County, KS 31 mi south · 56% at surface
Gove County, KS 33 mi west · 23% at surface
Rush County, KS 41 mi southeast · 55% at surface
Rooks County, KS 41 mi northeast · 48% at surface

Which formation it is

The largest mapped soluble unit here is the Niobrara Chalk (shale), Late Cretaceous in age, covering about 31% of the county. Next is the Ogallala Formation at 24%.

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

Trego County ranks 19 of 105 in Kansas for soluble rock at the surface, and sits above 89% of US counties on that measure.