Sinkhole risk in Valley County, MT: No soluble rock mapped

No soluble rock mapped

No soluble bedrock mapped.

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

What this means before you buy

No soluble bedrock is mapped here, so natural sinkholes are unlikely. Collapses from broken pipes or old mines are a separate risk.

Across 4,926 square miles, under one square mile of Valley County maps onto soluble rock. With about 7,434 residents (2 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 292 map points about 4.1 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 how these percentages are measured.

Counties around Valley County

The nearest county rated sinkhole country is Fall River County, SD, about 386 miles southeast. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Phillips County, MT 58 mi west · under 1% at surface
Daniels County, MT 60 mi northeast · 0% at surface
McCone County, MT 65 mi southeast · 0% at surface
Garfield County, MT 76 mi south · 0% at surface
Roosevelt County, MT 77 mi east · 0% at surface
Sheridan County, MT 101 mi east · 0% at surface

Against the rest of Montana

Valley County ranks 55 of 56 in Montana for soluble rock at the surface, and sits above 0% of US counties on that measure.