Minute mushrooms grow on the massive root of a Douglas-fir. It is the drip, drip, drip of water, though, that decorates the cave, building the bizarre and eerie sculptures. As easily as formations are created, they can also be dissolved. Rising warm air condenses on the cold ceiling. Acidified by carbon dioxide in the cave, this water dissolves formations.
Some formations provide information about the cave.
Water evaporated by air flowing in from outside leaves a residue of bumpy cave popcorn. Just as hikers use moss on the north side of trees, cavers use popcorn as a compass to find new passages or, when lost, their way out. Moonmilk is made of tiny calcite crystals but has the look and feel of cottage cheese. From early times it was a folk medicine smeared on livestock to heal wounds. But some folklore is true-moonmilk is created by the same type of bacteria used to make today's antibiotics.