Sinkhole risk in San Miguel County, CO: No soluble rock mapped
No soluble rock mapped
No soluble bedrock mapped.
- On soluble rock
- under 1%
- At or near the surface
- under 1%
- 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.
That works out to roughly 4 of San Miguel County's 1,287 square miles on soluble rock, 4 of them with the rock at or near the surface. With about 7,819 residents (6 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 294 map points about 2.1 miles apart, so a pocket smaller than that can be missed or overstated.
Read next: why gypsum and salt move faster than limestone, and how these percentages are measured.
Counties around San Miguel County
The nearest county rated sinkhole country is Emery County, UT, about 142 miles northwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.
- Dolores County, CO 20 mi south · 0% at surface
- Montrose County, CO 29 mi north · 1% at surface
- Ouray County, CO 36 mi east · under 1% at surface
- San Juan County, CO 44 mi east · 1% at surface
- Montezuma County, CO 47 mi south · 0% at surface
- Hinsdale County, CO 58 mi east · under 1% at surface
Which formation it is
The largest mapped soluble unit here is the Hermosa Fm (sandstone), Pennsylvanian in age, covering about under 1% of the county. Next is the Hermosa Fm at under 1%.
The county also lies over the Paradox Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.
Against the rest of Colorado
San Miguel County ranks 38 of 64 in Colorado for soluble rock at the surface, and sits above 51% of US counties on that measure.
- Pueblo County 45%
- Bent County 44%
- Otero County 42%
- Prowers County 35%
- Kiowa County 30%