Sinkhole risk in Putnam County, IL: 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 160 square miles, under one square mile of Putnam County maps onto soluble rock. With about 5,633 residents (35 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 297 map points about 0.7 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Putnam County

The nearest county rated sinkhole country is Jo Daviess County, IL, about 93 miles northwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Marshall County, IL 12 mi south · 0% at surface
Bureau County, IL 18 mi northwest · 0% at surface
LaSalle County, IL 24 mi northeast · 0% at surface
Stark County, IL 27 mi west · 0% at surface
Woodford County, IL 29 mi south · 0% at surface
Peoria County, IL 38 mi southwest · 0% at surface

Against the rest of Illinois

Putnam County ranks 85 of 102 in Illinois for soluble rock at the surface, and sits above 0% of US counties on that measure.