Sinkhole risk in San Bernardino County, CA: 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 421 of San Bernardino County's 20,068 square miles on soluble rock, 421 of them with the rock at or near the surface. With about 2,214,281 residents (110 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 285 map points about 8.4 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 San Bernardino County

The nearest county rated sinkhole country is Emery County, UT, about 416 miles northeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Riverside County, CA 79 mi south · under 1% at surface
Clark County, NV 114 mi northeast · 29% at surface
Orange County, CA 122 mi southwest · 6% at surface
Los Angeles County, CA 127 mi west · 1% at surface
San Diego County, CA 131 mi south · 0% at surface
Imperial County, CA 134 mi south · 0% at surface

What San Bernardino County is built on

The largest mapped soluble unit here is the Paleozoic marine rocks, undivided, unit 1 (Mojave Desert and Death Valley area) (limestone), Late Proterozoic to Jurassic in age, covering about under 1% of the county. Next is the Carboniferous marine rocks, unit 1 (Western Mojave Desert) at under 1%.

Against the rest of California

San Bernardino County ranks 13 of 58 in California for soluble rock at the surface, and sits above 58% of US counties on that measure.