Sinkhole risk in Canadian County, OK: Sinkhole country

Sinkhole country

Fast-dissolving gypsum or salt beds under a large part of the county.

On soluble rock: 40%
At or near the surface: 40%
Buried under cover: 0%

The next step for one property

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 356 of Canadian County's 897 square miles on soluble rock, 356 of them with the rock at or near the surface. With about 181,760 residents (203 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 393 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Canadian County

The closest county with no soluble rock mapped is Logan County, OK, about 39 miles northeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Kingfisher County, OK 28 mi north · 15% at surface
Oklahoma County, OK 32 mi east · 11% at surface
Blaine County, OK 34 mi northwest · 55% at surface
Caddo County, OK 34 mi southwest · 79% at surface
Grady County, OK 36 mi south · 42% at surface
Logan County, OK 39 mi northeast · 0% at surface

What Canadian County is built on

The largest mapped soluble unit here is the Dog Creek Shale (shale), Early Permian in age, covering about 18% of the county. Next is the Marlow Formation at 9%.

40% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

The county also lies over the Permian Basin, Anadarko Basin,Dalhart Basin, Palo Duro Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Oklahoma

Canadian County ranks 17 of 77 in Oklahoma for soluble rock at the surface, and sits above 84% of US counties on that measure.