SinkholeOdds

Sinkhole risk in Ulster County, NY: 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
7%
At or near the surface
0%
Buried under cover
7%

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 81 of Ulster County's 1,124 square miles on soluble rock. With about 182,977 residents (163 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 250 map points about 2.1 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 7% under cover still counts, and how these percentages are measured.

Counties around Ulster County

The nearest county rated sinkhole country is Union County, PA, about 160 miles southwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Which formation it is

The largest mapped soluble unit here is the Onondaga Limestone (shale), Lower to Middle Devonian in age, covering about 4% of the county. Next is the Rondout Formation at 2%.

Against the rest of New York

Ulster County ranks 56 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.