Sinkhole risk in Mason County, TX: Pockets of it

Pockets of it

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

On soluble rock: 46%
At or near the surface: 46%
Buried under cover: 0%

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 423 of Mason County's 929 square miles on soluble rock, 423 of them with the rock at or near the surface. With about 3,987 residents (4 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 396 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Mason County

The nearest county rated sinkhole country is Runnels County, TX, about 90 miles northwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Gillespie County, TX 32 mi southeast · 89% at surface
Llano County, TX 33 mi east · 11% at surface
Kimble County, TX 34 mi southwest · 97% at surface
McCulloch County, TX 35 mi north · 48% at surface
Menard County, TX 39 mi west · 93% at surface
San Saba County, TX 40 mi northeast · 59% at surface

The rock underneath

The largest mapped soluble unit here is the Hensell Sand (limestone), Early Cretaceous; Comanchean Series in age, covering about 9% of the county. Next is the Riley Formation showing Lion Mountain Sandstone and Cap Mountain Limestone Members, undivided at 9%.

Against the rest of Texas

Mason County ranks 55 of 254 in Texas for soluble rock at the surface, and sits above 86% of US counties on that measure.