Sinkhole risk in Carlton County, MN: 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: 26%
At or near the surface: 0%
Buried under cover: 26%

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 226 of Carlton County's 861 square miles on soluble rock. With about 36,745 residents (43 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 389 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 26% under cover still counts, and how these percentages are measured.

Counties around Carlton County

The nearest county rated sinkhole country is Vernon County, WI, about 226 miles southeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Pine County, MN 35 mi south · 1% at surface
Aitkin County, MN 36 mi west · 0% at surface
Douglas County, WI 38 mi east · 0% at surface
Burnett County, WI 53 mi south · 0% at surface
Kanabec County, MN 54 mi southwest · 0% at surface
Washburn County, WI 65 mi southeast · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Fond du Lac Formation (shale), Middle Proterozoic in age, covering about 17% of the county. Next is the Hinckley Sandstone at 10%.

Against the rest of Minnesota

Carlton County ranks 16 of 87 in Minnesota for soluble rock at the surface, and sits above 0% of US counties on that measure.