Hughes Mountain
Hughes Mountain Conservation Area is a geological rarity. In fact, it may be one of the rarest rock formations in the United States. The rock on top of the mountain formed from a process called columnar jointing. Columnar jointing is similar to when mud dries and cracks into hexagonal formations. Columnar jointing is rare on it's own, with examples such as the Devil's Tower in Wyoming or Giant's Causeway in Ireland. Most examples of columnar jointing occur in basalt rock, but in Missouri it occured in rhylolite. That coupled with the fact that the rock is 1.485 billion years old and it is located far away from a plate boundary (where most lava flow occurs) leads me to believe that this may be one of the rarest formations in the US.
Trail:
Hughes Mountain Trail is only 1.6 miles long, but the scenic vista, prickly pear cacti, and rare rock formations make the short hike worth the trip.