Sinkhole risk in Trempealeau County, WI: 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: 5%
At or near the surface: 5%
Buried under cover: 0%

What this means before you buy

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

That works out to roughly 33 of Trempealeau County's 733 square miles on soluble rock, 33 of them with the rock at or near the surface. With about 30,801 residents (42 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 309 map points about 1.5 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 Trempealeau County

The nearest county rated sinkhole country is Vernon County, WI, about 55 miles southeast. None of the 6 closest counties land in the same band, so Trempealeau County stands out from its surroundings.

Buffalo County, WI 21 mi west · 31% at surface
Jackson County, WI 28 mi east · 0% at surface
Eau Claire County, WI 29 mi north · 0% at surface
La Crosse County, WI 30 mi southeast · 22% at surface
Winona County, MN 30 mi southwest · 27% at surface
Pepin County, WI 32 mi northwest · 23% at surface

What Trempealeau County is built on

The largest mapped soluble unit here is the Prairie du Chien Group (shale), Lower Ordovician in age, covering about 5% of the county.

Against the rest of Wisconsin

Trempealeau County ranks 15 of 72 in Wisconsin for soluble rock at the surface, and sits above 62% of US counties on that measure.