SinkholeOdds

Sinkhole risk in Bear Lake County, ID: Pockets of it

Pockets of it

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

On soluble rock
45%
At or near the surface
45%
Buried under cover
0%

The next step for one property

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 442 of Bear Lake County's 976 square miles on soluble rock, 442 of them with the rock at or near the surface. With about 6,779 residents (7 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 344 map points about 1.7 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 Bear Lake County

The nearest county rated sinkhole country is Emery County, UT, about 229 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Siltstone, evaporites, and redbeds; Late Jurassic Cordilleran retroarc-foreland-basin deposits; southeastern Idaho (siltstone), Late Jurassic in age, covering about 13% of the county. Next is the Dolostone, limestone, arenite, chert, and conglomerate; Ordovician marine continental-shelf deposits; southeastern Idaho at 9%.

13% 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 Idaho

Bear Lake County ranks 1 of 44 in Idaho for soluble rock at the surface, and sits above 86% of US counties on that measure.