Sinkhole risk in Piscataquis County, ME: 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: under 1%
Buried under cover: 4%

What to do about a house in Piscataquis County

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

That works out to roughly 162 of Piscataquis County's 3,961 square miles on soluble rock, 24 of them with the rock at or near the surface. With about 17,432 residents (4 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 315 map points about 3.5 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 Piscataquis County

The nearest county rated sinkhole country is Union County, PA, about 525 miles southwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Penobscot County, ME 41 mi southeast · 0% at surface
Somerset County, ME 50 mi southwest · 0% at surface
Aroostook County, ME 60 mi northeast · 0% at surface
Franklin County, ME 91 mi southwest · 0% at surface
Washington County, ME 98 mi southeast · 0% at surface
Waldo County, ME 100 mi south · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Ordovician - Cambrian Chase Brook Formation (slate), Ordovician - Cambrian in age, covering about 2% of the county. Next is the Silurian Sangerville Formation limestone member at 1%.

Against the rest of Maine

Piscataquis County ranks 3 of 16 in Maine for soluble rock at the surface, and sits above 53% of US counties on that measure.