Sinkhole risk in Bannock 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: 29%
At or near the surface: 29%
Buried under cover: 0%

What to do about a house in Bannock 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 324 of Bannock County's 1,112 square miles on soluble rock, 324 of them with the rock at or near the surface. With about 91,010 residents (82 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 506 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Bannock County

The nearest county rated sinkhole country is Emery County, UT, about 266 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Power County, ID 31 mi west · 18% at surface
Caribou County, ID 35 mi east · 24% at surface
Bingham County, ID 37 mi north · 8% at surface
Oneida County, ID 38 mi southwest · 44% at surface
Franklin County, ID 41 mi southeast · 37% at surface
Bear Lake County, ID 54 mi southeast · 45% at surface

What Bannock County is built on

The largest mapped soluble unit here is the Arenite, carbonate, conglomerate, and shale; Late Proterozoic rifted continental margin; southeastern Idaho (arenite), Late Proterozoic in age, covering about 12% of the county. Next is the Limestone, arenite, shale, dolostone, and siltstone; Upper Proterozoic to Cambrian marine continental-shelf deposits; southeastern Idaho at 6%.

Against the rest of Idaho

Bannock County ranks 4 of 44 in Idaho for soluble rock at the surface, and sits above 79% of US counties on that measure.