Sinkhole risk in Gage 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: 50%
At or near the surface: 0%
Buried under cover: 50%

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 422 of Gage County's 851 square miles on soluble rock. With about 21,687 residents (25 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 399 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 50% under cover still counts.

Counties around Gage County

The nearest county rated sinkhole country is Dickinson County, KS, about 99 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Johnson County, NE 24 mi northeast · 0% at surface
Pawnee County, NE 25 mi east · 0% at surface
Jefferson County, NE 25 mi west · 5% at surface
Saline County, NE 30 mi northwest · 0% at surface
Marshall County, KS 34 mi south · 2% at surface
Lancaster County, NE 37 mi north · 0% at surface

What Gage County is built on

The largest mapped soluble unit here is the Chase Group (limestone), Permian in age, covering about 50% of the county.

The county also lies over the Northern Anadarko Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Nebraska

Gage County ranks 58 of 93 in Nebraska for soluble rock at the surface, and sits above 0% of US counties on that measure.