SinkholeOdds

Sinkhole risk in Lincoln County, WY: Pockets of it

Pockets of it

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

On soluble rock
27%
At or near the surface
27%
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 1,096 of Lincoln County's 4,075 square miles on soluble rock, 1,096 of them with the rock at or near the surface. With about 21,000 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 268 map points about 3.9 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Lincoln County

The nearest county rated sinkhole country is Emery County, UT, about 223 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Which formation it is

The largest mapped soluble unit here is the Stump Formation, Preuss Sandstone or Redbeds, and Twin Creek Limestone (fine-grained mixed clastic), Middle Jurassic-Upper Jurassic in age, covering about 8% of the county. Next is the Ankareh Formation, Thaynes Limestone, Woodside Shale, and Dinwoody Formation at 6%.

8% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

The county also lies over the Wyoming Thrust belt, 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 Wyoming

Lincoln County ranks 2 of 23 in Wyoming for soluble rock at the surface, and sits above 78% of US counties on that measure.