I once wore my Chacos six weeks straight on a road trip through Latin America. They survived scrambles up the ruins of Tikal, a six-hour march into a remote village in Guatemala's Cuchumatanes mountains, and a lot of sweaty hours in the car. The only downside: I acquired weird tan lines on my feet.
Try Chaco's Z/2 Vibram Unaweep ($95; chacousa.com). It's simple, but durable, with a wrap-around toe loop that keeps your feet from sliding out over the footbed, even on wicked descents, and has a rugged Vibram sole. The Unaweep has just the right amount of quick-drying webbing to keep your feet in place and comfortable, without being annoyingly complicated to adjust. Then again, I can't remember the last time I had to adjust my Chacos.
Teva, a brand synonymous with having fun on the river, also makes a great hiking sandal, especially if you plan to be splashing around in water afterward. The sole of the Open Toachi ($90; teva.com) is made out of a rubber composite that blends function with durability, and the "drain frame" platform allows the water to escape, while keeping sand and debris from getting underfoot. Plus, the anti-microbial technology ensures that you're feet won't be sprouting any nasty fungus.