Sinkhole risk in Judith Basin County, MT: Pockets of it

Pockets of it

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

On soluble rock: 33%
At or near the surface: 33%
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 610 of Judith Basin County's 1,870 square miles on soluble rock, 610 of them with the rock at or near the surface. With about 2,111 residents (1 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 304 map points about 2.5 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Judith Basin County

The nearest county rated sinkhole country is Fall River County, SD, about 423 miles southeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Meagher County, MT 42 mi southwest · 49% at surface
Wheatland County, MT 43 mi southeast · 6% at surface
Fergus County, MT 52 mi east · 12% at surface
Cascade County, MT 53 mi west · 18% at surface
Chouteau County, MT 59 mi north · 0% at surface
Golden Valley County, MT 70 mi southeast · 4% at surface

What Judith Basin County is built on

The largest mapped soluble unit here is the Mississippian, undifferentiated (carbonate), Mississippian in age, covering about 20% of the county. Next is the Cambrian, undifferentiated at 5%.

3% 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 Montana

Judith Basin County ranks 3 of 56 in Montana for soluble rock at the surface, and sits above 81% of US counties on that measure.