SinkholeOdds

Sinkhole risk in Griggs County, ND: 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
2%
At or near the surface
0%
Buried under cover
2%

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 11 of Griggs County's 709 square miles on soluble rock. With about 2,227 residents (3 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 378 map points about 1.4 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 Griggs County

The nearest county rated sinkhole country is Boyd County, NE, about 316 miles south. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Which formation it is

The largest mapped soluble unit here is the Niobrara and Carlile Formations, Undivided (limestone), Cretaceous in age, covering about 2% of the county.

Against the rest of North Dakota

Griggs County ranks 23 of 53 in North Dakota for soluble rock at the surface, and sits above 0% of US counties on that measure.