Sinkhole risk in Valley 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: 1%
At or near the surface: 1%
Buried under cover: 0%

What to do about a house in Valley County

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

That works out to roughly 40 of Valley County's 3,665 square miles on soluble rock, 40 of them with the rock at or near the surface. With about 12,777 residents (3 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 264 map points about 3.7 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Valley County

The nearest county rated sinkhole country is Emery County, UT, about 476 miles southeast. None of the 6 closest counties land in the same band, so Valley County stands out from its surroundings.

Adams County, ID 41 mi west · under 1% at surface
Boise County, ID 60 mi south · 0% at surface
Washington County, ID 64 mi southwest · 0% at surface
Gem County, ID 67 mi southwest · 0% at surface
Idaho County, ID 69 mi north · under 1% at surface
Custer County, ID 78 mi southeast · 15% at surface

The rock underneath

The largest mapped soluble unit here is the Quartzite and marble; Middle Proterozoic Hoodoo Quartzite; southern Belt province (quartzite), Middle Proterozoic in age, covering about 1% of the county.

Against the rest of Idaho

Valley County ranks 21 of 44 in Idaho for soluble rock at the surface, and sits above 56% of US counties on that measure.