Sinkhole risk in Sherman County, KS: 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: 9%
At or near the surface: 9%
Buried under cover: 0%

What this means before you buy

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

That works out to roughly 93 of Sherman County's 1,056 square miles on soluble rock, 93 of them with the rock at or near the surface. With about 5,796 residents (5 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 400 map points about 1.6 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Sherman County

The nearest county rated sinkhole country is Harlan County, NE, about 136 miles northeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Wallace County, KS 29 mi south · 23% at surface
Cheyenne County, KS 30 mi north · 19% at surface
Thomas County, KS 34 mi east · 8% at surface
Logan County, KS 43 mi southeast · 11% at surface
Rawlins County, KS 46 mi northeast · 24% at surface
Kit Carson County, CO 47 mi west · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Ogallala Formation (arkose), Miocene in age, covering about 9% of the county.

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

Sherman County ranks 73 of 105 in Kansas for soluble rock at the surface, and sits above 67% of US counties on that measure.