The pantie tree under Chr 5 in the back bowls of Vail started after a lonely wool scarf hung in that tree for years by itself. Suddenly another article of clothing appeared, and it was all on. Soon the tree became two trees, then finally three trees. Several years back, one of the trees died and fell over. The ski patrol (armed with long sticks and rubber gloves) collected the articles and placed them up in one of the remaining trees. Now everything from bras, panties, boxers, corsets, tighty whitey's, and even tennis shoes all hang from the tree.
As a side note, someone decided to create a similar tree at Beaver Creek. Various items appeared, until the management finally decided it was "not in keeping with the family atmosphere of Beaver Creek" and assigned an employee to ride the chair, where he had it stopped where he could reach the articles. While retrieving said articles, the employee almost falls out of the chair. The tree was deemed a danger and a nuisance, and was summarily cut down. Local USFS officials hear of this tree felling, and investigates. It turns out the ski area had no permit to remove the offending tree.
RESULT? $5000 fine to Vail Resorts for illegally removing a tree without a permit.