This salient bit of advice sounds self-evident for a backpack trip, but you’d be surprised how many novice hikers on guided backpacking trips in Montana backcountry, Yellowstone or anywhere really, want to bring two pair of trousers, two pair of gloves, two sets of longjohns, two or more T-shirts, two pair of camp/stream shoes and yes, multiple underwear changes. Every ounce counts! And when you duplicate numerous items, you may in fact end up weighing yourself down to the point of ruining your backcountry trip. We’ve seen that happen. Pack light, don’t duplicate, and you’ll love backpacking!
Anyway, do you really need to change trousers mid-trip? Who are you trying to impress, anyway? And what about duplicate longjohns? I mean, soldiers in World War II used to wear one set of longies all winter without washing them, because the body oils that gradually impregnate the fabric add insulation. So you sure don’t need to have two sets for a simple week-long backpack trip. Anyway, if your cloths really get to stinkin’ — which sweaty T-shirts sometimes do in warm summer weather — don’t duplicate but rinse them in the creek after you get to camp (downstream from where we get our drinking water, please) and hang them in the sun to dry. Viola’! Clean cloths! Or at least they’ll be clean enough not to offend the local squirrels.
I could go on about this, but I won’t. You get the picture. To travel successfully through the wilderness, one must leave some civilized habits behind. Follow the Big Wild Clothing/Personal Gear List without adding items and you’ll be fine. If the list says “one,” then please bring just one. And have a great walk in the wilds!