Will and Zak are now over a month into their navigation of the Colorado River from source to sea. They've had company for a while, but now they're going back to being by themselves. In Desolation and Labyrinth Canyons, they experience solitude that gets them pondering why they're attempting this trip. It can be a slog—it's Fall, it's cold, and some of their meals are pretty disgusting. But the scenery's magnificent, the wildlife is plentiful along the river, and the journey keeps calling.