Sinkhole risk in Iron County, UT: 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: 2%
Buried under cover: 0%

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 59 of Iron County's 3,296 square miles on soluble rock, 59 of them with the rock at or near the surface. With about 65,936 residents (20 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 326 map points about 3.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Iron County

The nearest county rated sinkhole country is Emery County, UT, about 159 miles northeast. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Beaver County, UT 31 mi north · 8% at surface
Washington County, UT 46 mi south · 16% at surface
Piute County, UT 70 mi northeast · 0% at surface
Millard County, UT 73 mi north · 18% at surface
Lincoln County, NV 87 mi west · 17% at surface
Kane County, UT 93 mi southeast · 15% at surface

What Iron County is built on

The largest mapped soluble unit here is the Jurassic (1) sedimentary rocks in southeastern Utah (sandstone), Middle Jurassic in age, covering about under 1% of the county. Next is the Triassic (1) sedimentary rocks in Salt southwestern Utah at under 1%.

Against the rest of Utah

Iron County ranks 26 of 29 in Utah for soluble rock at the surface, and sits above 57% of US counties on that measure.