Sinkhole risk in Snyder 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: 41%
At or near the surface: 38%
Buried under cover: 4%

What this means before you buy

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 136 of Snyder County's 329 square miles on soluble rock, 124 of them with the rock at or near the surface. With about 39,627 residents (121 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 254 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Snyder County

The nearest county rated sinkhole country is Union County, PA, about 14 miles north, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Union County, PA 14 mi north · 53% at surface
Northumberland County, PA 20 mi east · 26% at surface
Juniata County, PA 23 mi southwest · 45% at surface
Perry County, PA 27 mi south · 34% at surface
Dauphin County, PA 28 mi southeast · 8% at surface
Montour County, PA 28 mi northeast · 40% at surface

Which formation it is

The largest mapped soluble unit here is the Hamilton Group (shale), Devonian in age, covering about 18% of the county. Next is the Clinton Group at 10%.

Against the rest of Pennsylvania

Snyder County ranks 9 of 67 in Pennsylvania for soluble rock at the surface, and sits above 83% of US counties on that measure.