Sinkhole risk in Skamania County, WA: Not karst, but voids possible

Not karst, but voids possible

No soluble bedrock; some pseudokarst (piping or lava-tube ground).

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

What this means before you buy

Not true karst, but soil piping or lava tubes can still open voids - mention it to an inspector.

Across 1,658 square miles, under one square mile of Skamania County maps onto soluble rock. With about 12,660 residents (8 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 325 map points about 2.3 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Skamania County

The nearest county rated sinkhole country is Emery County, UT, about 749 miles southeast. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Clark County, WA 31 mi southwest · 0% at surface
Cowlitz County, WA 37 mi west · 0% at surface
Hood River County, OR 38 mi south · 0% at surface
Multnomah County, OR 40 mi southwest · 0% at surface
Lewis County, WA 43 mi northwest · 0% at surface
Columbia County, OR 54 mi west · 0% at surface

Against the rest of Washington

Skamania County ranks 32 of 39 in Washington for soluble rock at the surface, and sits above 0% of US counties on that measure.