There's probably a little bit of Huck Finn in all of us that yearns for the chance to drift quietly down river, or challenge the bubbling rapids of a mountain stream, savoring nature at its' best. Tubing can be as simple or involved as you like, and as safe or risky as you make it. It can be done in small or large groups for a few minutes, a few hours or a few days if you are so inclined. There are no boats to trailer, no outboards to gas up, and relatively little expense or preparation. River tubing has enjoyed tremendous popu-larity in Arizona over the past decades and more reports are...