Sinkhole risk in Allegany County, MD: Pockets of it

Pockets of it

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

On soluble rock: 24%
At or near the surface: 24%
Buried under cover: 0%

The next step for one property

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 101 of Allegany County's 422 square miles on soluble rock, 101 of them with the rock at or near the surface. With about 67,097 residents (159 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 572 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Allegany County

The nearest county rated sinkhole country is Winchester city, VA, about 41 miles southeast. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Mineral County, WV 20 mi southwest · 12% at surface
Hampshire County, WV 21 mi south · 8% at surface
Morgan County, WV 24 mi east · 7% at surface
Bedford County, PA 29 mi north · 26% at surface
Garrett County, MD 31 mi west · 8% at surface
Somerset County, PA 31 mi northwest · 5% at surface

What Allegany County is built on

The largest mapped soluble unit here is the Oriskany Group including Ridgeley Sandstone and Shriver Chert (orthoquartzite), Devonian in age, covering about 7% of the county. Next is the Monongahela Formation at 6%.

Against the rest of Maryland

Allegany County ranks 3 of 24 in Maryland for soluble rock at the surface, and sits above 77% of US counties on that measure.