Sinkhole risk in Stevens County, WA: 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%

The next step for one property

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

That works out to roughly 84 of Stevens County's 2,477 square miles on soluble rock, 84 of them with the rock at or near the surface. With about 49,015 residents (20 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 3.0 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 Stevens County

The nearest county rated sinkhole country is Emery County, UT, about 739 miles southeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Pend Oreille County, WA 30 mi east · 2% at surface
Ferry County, WA 32 mi west · under 1% at surface
Bonner County, ID 57 mi east · 1% at surface
Spokane County, WA 57 mi south · 0% at surface
Lincoln County, WA 61 mi southwest · 0% at surface
Boundary County, ID 66 mi northeast · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Cambrian limestone and dolomite (limestone), Early Cambrian-Middle Ordovician in age, covering about 3% of the county. Next is the Precambrian rocks, undivided at under 1%.

Against the rest of Washington

Stevens County ranks 2 of 39 in Washington for soluble rock at the surface, and sits above 60% of US counties on that measure.