Sinkhole risk in Nez Perce County, ID: 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: 3%
At or near the surface: 3%
Buried under cover: 0%

What to do about a house in Nez Perce County

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

That works out to roughly 21 of Nez Perce County's 848 square miles on soluble rock, 21 of them with the rock at or near the surface. With about 42,847 residents (51 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 484 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Nez Perce County

The nearest county rated sinkhole country is Emery County, UT, about 591 miles southeast. None of the 6 closest counties land in the same band, so Nez Perce County stands out from its surroundings.

Lewis County, ID 17 mi southeast · under 1% at surface
Asotin County, WA 25 mi southwest · 0% at surface
Latah County, ID 34 mi north · 0% at surface
Garfield County, WA 38 mi west · 0% at surface
Whitman County, WA 54 mi northwest · 0% at surface
Columbia County, WA 55 mi west · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Limestone, slate; Upper Triassic greenschist-facies metamorphic rocks; western Idaho, Blue Mountains island-arc complex; (limestone), Late Triassic in age, covering about 3% of the county.

Against the rest of Idaho

Nez Perce County ranks 18 of 44 in Idaho for soluble rock at the surface, and sits above 59% of US counties on that measure.