SinkholeOdds

Sinkhole risk in Cedar County, NE: 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
61%
At or near the surface
0%
Buried under cover
61%

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 451 of Cedar County's 740 square miles on soluble rock. With about 8,262 residents (11 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 348 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and why the 61% under cover still counts.

Counties around Cedar County

The nearest county rated sinkhole country is Knox County, NE, about 32 miles west, close enough that the same rock may run under the county line. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Niobrara Formation (limestone), Late Cretaceous in age, covering about 50% of the county. Next is the Pierre Shale at 11%.

11% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

Against the rest of Nebraska

Cedar County ranks 44 of 93 in Nebraska for soluble rock at the surface, and sits above 0% of US counties on that measure.