Sinkhole risk in Summit County, CO: 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: 4%
At or near the surface: 4%
Buried under cover: 0%

What to do about a house in Summit County

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 25 of Summit County's 608 square miles on soluble rock, 25 of them with the rock at or near the surface. With about 30,882 residents (51 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 465 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Summit County

The nearest county rated sinkhole country is Emery County, UT, about 249 miles west. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Clear Creek County, CO 25 mi east · 0% at surface
Eagle County, CO 30 mi west · 22% at surface
Lake County, CO 31 mi south · 5% at surface
Grand County, CO 34 mi north · 6% at surface
Gilpin County, CO 36 mi northeast · 0% at surface
Park County, CO 41 mi southeast · 13% at surface

What Summit County is built on

The largest mapped soluble unit here is the Colorado Group (shale), Cretaceous in age, covering about 4% of the county. Next is the Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite at under 1%.

Against the rest of Colorado

Summit County ranks 22 of 64 in Colorado for soluble rock at the surface, and sits above 62% of US counties on that measure.