Every year, my friend Carol goes on a backpacking trip with a group of women, to honor one of the women's sister who is a breast cancer survivor. This year they hiked in Yosemite National Park.
The hike resulted in a first for my collection - a postcard that was packed out by mule from May Lake (see postcard, upper left corner) while they were still camping, and mailed from the valley floor. I believe the stamp on the postcard refers to it as "US Mule", as opposed to "US Mail". Cool!