Two of us take the optional detour to Ribbon Falls, about a quarter mile out of our way. Ribbon Falls lies in a narrow side canyon, and feeds moss and foliage that I would sooner expect to see in a tropical forest. The spray of the water from above feels great as our bodies welcome the respite from the intense heat.

Mile 15: I'm starting to feel tired, but know I still have a long way to go. We reach Cottonwood Campground around Noon, a small, shady rest area

that allows us to rest briefly and once again re-fill our packs with water.

Before long we press again a further mile until we are at the North Rim residence house, occupied by a family paid to monitor a nearby pump house. The residence house is situated 5,200 feet above sea level, much short of our destination at 8,240 feet. This point marks the transition where the trail begins to rise in earnest - now there is no mistaking that we are making our way out.