Sinkhole risk in Sequoyah County, OK: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock: 3%
At or near the surface: 3%
Buried under cover: 0%

The next step for one property

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 22 of Sequoyah County's 674 square miles on soluble rock, 22 of them with the rock at or near the surface. With about 40,555 residents (60 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 308 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Sequoyah County

The nearest county rated sinkhole country is Adair County, OK, about 28 miles north, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Haskell County, OK 28 mi southwest · 0% at surface
Adair County, OK 28 mi north · 79% at surface
Crawford County, AR 29 mi east · 0% at surface
Cherokee County, OK 31 mi northwest · 66% at surface
Sebastian County, AR 34 mi southeast · 0% at surface
Muskogee County, OK 36 mi west · 2% at surface

Which formation it is

The largest mapped soluble unit here is the Bloyd and Hale Formations (limestone), Early Pennsylvanian in age, covering about 2% of the county. Next is the Pitkin + Fayetteville + Hindsville + Moorefield Formations at under 1%.

Against the rest of Oklahoma

Sequoyah County ranks 58 of 77 in Oklahoma for soluble rock at the surface, and sits above 60% of US counties on that measure.