Ah, the platypus. Waddling along at the very pinnacle of evolution, sharing that exalted summit with the likes of Brangelina and Moose's Tooth Fairweather IPA. Also, taking up space in "the pig" as we fondly named our expedition sled that glided along behind us effortlessly on the Kahiltna. Of course, we also called the pig many other names that rhymed with pucker. Always with love in our hearts, though. We love the pig.
And we do love the Platy. Here's the 411: fly into Kahiltna Base Camp and you're immediately sharing space with a few hundred of your closest friends. Assuming your closest friends are foul-assed climbers polluting every piece of meltable snow in sight. Anyway, you need water, so you either have to pack it in or find some clean snow. We're here to argue for packing it in.
The beauty of the Platypus one gallon water tank is that you can pull it in the pig up to camp two, and then you don't have to melt snow. One gallon is four quarts/liters, enough for two people to cook and fill their bottles for day two on the mountain. The tank itself only weighs three ounces, and is easily cached or carried if you're through-hiking. The zipper closure holds tight, the handle is perfectly located for pouring, and not only do you save the time and effort to melt snow but you save a bit of fuel as well.

What do the Wright Bros., Ernest Shackleton and Count Zeppelin have in common? Well not only are they all dead, it turns out they
The Nalgene Elevation hydration pack is part of a new series of hydration packs that feature real innovation in design. My favorite feature: a magnetic clip that secures the bite valve to the sternum strap.
Another optional piece of gear. Optional, that is, in the same way that dying of thirst because your water bottle is frozen solid at altitude is optional. If you prefer your water in liquid form you'll want one of these.
