Southeast Missouri / Lead Belt / Mississippi Corridor
Hughes Mountain puts columned rhyolite south of Potosi
Hughes Mountain Natural Area gives Washington County a sourced geologic landmark of Precambrian rhyolite, columned rock, glades, and a short trail.
Hughes Mountain adds a Washington County texture that cannot be swapped onto a generic Ozark page. MDC places the natural area south of Potosi and describes Precambrian rock outcrops tied to ancient volcanic activity in the St. Francois Mountains.
The local feature is the rhyolite formation called Devil’s Honeycomb. MDC explains that molten rock cooled and cracked into multi-sided columns, and it lists a one-mile trail to the top of Hughes Mountain.
For a visitor or local reader, this is not just “public land.” It is a county-specific geology note, and the MDC page is the right place to check access, rules, and directions before going.
That makes Hughes Mountain one of the county’s clearest “wait, really?” outdoor stories.
Where to see it
- Hughes Mountain Natural Area
Use MDC for trail access, natural-area rules, and columned-rhyolite context.
References
More from Washington County: browse every local note for the county.
Last checked against the sources above: July 16, 2026.