Sinkhole risk in Wilbarger County, TX: Sinkhole country

Sinkhole country

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

On soluble rock: 39%
At or near the surface: 39%
Buried under cover: 0%

What to do about a house in Wilbarger County

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

That works out to roughly 378 of Wilbarger County's 971 square miles on soluble rock, 378 of them with the rock at or near the surface. With about 12,455 residents (13 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 314 map points about 1.8 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Wilbarger County

The closest county with no soluble rock mapped is Tillman County, OK, about 27 miles northeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Tillman County, OK 27 mi northeast · 0% at surface
Wichita County, TX 31 mi east · under 1% at surface
Hardeman County, TX 32 mi northwest · 63% at surface
Baylor County, TX 32 mi south · 50% at surface
Foard County, TX 34 mi west · 72% at surface
Jackson County, OK 36 mi north · 34% at surface

What Wilbarger County is built on

The largest mapped soluble unit here is the Clear Fork Group (mudstone), Permian; Leonard Series in age, covering about 37% of the county. Next is the Lueders Formation at 2%.

37% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

Against the rest of Texas

Wilbarger County ranks 64 of 254 in Texas for soluble rock at the surface, and sits above 83% of US counties on that measure.