While Thoreau wrote that 'in wilderness is the preservation of the world,' when it comes to self preservation there are necessities and then there is what gets left behind. Everything in a backpack is included based on its value in a survival situation. If you're carrying one item it means that there isn't room for another--and you must calculate which is more important if, say, the plane doesn't return on time, a bear devours five days worth of provisions in camp with no hope of resupply, or you fall and break your leg on some nameless shale slide.

- CD