Sinkhole risk in Huntingdon County, PA: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 35%
At or near the surface: 35%
Buried under cover: 0%

What to do about a house in Huntingdon County

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 310 of Huntingdon County's 875 square miles on soluble rock, 310 of them with the rock at or near the surface. With about 43,359 residents (50 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 254 map points about 1.9 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Huntingdon County

The nearest county rated sinkhole country is Washington County, MD, about 57 miles south. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Blair County, PA 19 mi west · 36% at surface
Mifflin County, PA 21 mi northeast · 45% at surface
Juniata County, PA 31 mi east · 45% at surface
Centre County, PA 34 mi north · 40% at surface
Fulton County, PA 36 mi south · 19% at surface
Franklin County, PA 37 mi south · 44% at surface

What Huntingdon County is built on

The largest mapped soluble unit here is the Clinton Group (shale), Silurian in age, covering about 10% of the county. Next is the Mauch Chunk Formation at 6%.

Against the rest of Pennsylvania

Huntingdon County ranks 13 of 67 in Pennsylvania for soluble rock at the surface, and sits above 82% of US counties on that measure.