I use state park & camping area porta-potties. I use them at truck-weighing scales if it is after trucker's hours. I go in convenience stores, if there is one. I go behind trees when there isn't. I have slid down scree to go behind the one tree in the alpine environment.

I've learned to drop my shorts and go, FAST. I've used tissue, no tissue, and leaves, depending on what I'm doing.

It helps to develop a less-sensitive sense of modesty!