Sinkhole risk in Marion County, OR: Not karst, but voids possible
Not karst, but voids possible
No soluble bedrock; some pseudokarst (piping or lava-tube ground).
- On soluble rock
- 0%
- At or near the surface
- 0%
- Buried under cover
- 0%
The next step for one property
Not true karst, but soil piping or lava tubes can still open voids - mention it to an inspector.
Across 1,181 square miles, under one square mile of Marion County maps onto soluble rock. With about 352,867 residents (299 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 419 map points about 1.7 miles apart, so a pocket smaller than that can be missed or overstated.
Read next: how ground with no limestone still opens up, and how these percentages are measured.
Counties around Marion County
The nearest county rated sinkhole country is Emery County, UT, about 731 miles southeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.
- Clackamas County, OR 26 mi northeast · 0% at surface
- Linn County, OR 29 mi south · 0% at surface
- Polk County, OR 40 mi west · 3% at surface
- Yamhill County, OR 43 mi northwest · 0% at surface
- Multnomah County, OR 45 mi north · 0% at surface
- Benton County, OR 50 mi southwest · 0% at surface
Against the rest of Oregon
Marion County ranks 28 of 36 in Oregon for soluble rock at the surface, and sits above 0% of US counties on that measure.
- Baker County 14%
- Josephine County 9%
- Grant County 4%
- Polk County 3%
- Jackson County 2%