The Cathoula Formation -- formed some 35 million years ago during the Oligocene Period -- consists of buff-colored sandstone flecked with mica, quartzite, and trace amounts of uranium, all originating from volcanic ash. Deep within the Upland Island Wilderness Area, where the formation cuts across a ridgeline, nearby seeps have uncovered numerous rocks and large boulders. It's quite a rare sight for the Pineywoods of East Texas.
Your best bet for parking is along Forest Service Road 330, at the coordinates listed below. As you head towards the cache you'll skirt several bogs of carnivorous pitcher plants, along with sphagnum moss seeps. Watch your step lest you trample these environmentally sensitive areas.
Upon reaching the listed coordinates, you'll be looking for a camouflaged Nalgene bottle. Bring your own pen to sign the log. And be sure to take a few minutes (or hours) to explore the fascinating boulders strewn out amongst the longleaf pines.