What an experience! After hiking to the top of Upper Yosemite Falls in the morning (around 9 miles roundtrip with almost 4000 total vertical feet), trying to beat the traffic of Memorial Day weekend, I took the afternoon off by going through the Visitor Center and checking out some sunset picture sites.
Then what became the highlight of the day began with a nine mile run in roughly 8:00 per mile (I don't know the exact distance or even the time since I didn't wear my watch - a truly liberating experience) from one end of Yosemite Valley to effectively the other end and back. It was entirely on the Valley Loop Trail, which was mostly dirt but occasionally showed its age with some really beat up asphalt. Running through the woods while in sight of and within hearing range of the various waterfalls was a lifetime experience.
This is truly one of the reasons I run...I can climb high and walk far, and then have a life-list run all in the span of ten or so hours.