I climbed Mt. Whitney in the summer of 2005 - just before my daughter left for college. We hiked the 22-mile round trip in one day with my daughter's friend and her mother (who happily is my friend). I'll never forget the looks on the girls' faces when we went to the ranger station to pick up our permits and the ranger handed us black plastic "waste" bags, and she wasn't talking about our trash. One of the girls pinched the bag between her thumb and forefinger. The majority of the Mt. Whitney hike is done above the tree line, so there is not much privacy anyway. The ranger said that the helicopters didn't have time to clean out the porta-potties at the summit campground as they were being used to fight fires. We were encouraged to pack out our waste bags. =O
Some have asked about the "toileting" facilities on Mt. Kilimanjaro. I know that it is a well-traveled trail like the Mt. Whitney trail. Permits are required on Mt. Whitney to lessen the human impact, and guides are required on the Mt.Kilimanjaro trail for the same reason. I have been told that porta-potties are placed at strategic locations along the Mt. Kilimanjaro trail. Kind of ruins the mystique for me, but...when I am hiking that trail, I'm sure I will choose practicality over mystique!