I want to buy my cousin a pack to carry his skis up the mountain. He's 18 years old, just started school in Flagstaff, AZ. Should be some good back country stuff for him to try. What's a good pack for back country skiing?
Ah, I envy your cousin! I think Flagstaff would be a great place to go to school. Nice little town, two hours from Phoenix if you need some big-city excitement, close to lots of great backcountry, not to mention the Grand Canyon.
Quite a few pack makers produce ski-oriented packs. They're basically simply good day packs with extra straps or pockets for holding skis, snowboards, maybe an avalanche shovel. Plus the clever ones add some winter-specific features.
Osprey's Kode 30 ($139) is a good example. It's essentially a nice, clean daypack with 1,800 cubic inches of capacity and a suspension that can handle loads up to 30 to 35 pounds. It has a large rear panel/pocket that can hold a snowboard vertically, and straps that let you attach skis diagonally or in an A-shaped pattern. Then it adds some nice touches such as an insulated sleeve for a hydration tube, internal sleeves to protect goggles and hold snow probes, and an internal pocket specifically meant to hold wet gear and keep it separate from dry stuff.
Arc'Teryx's Silo 30 ($170) is the same size as the Kode, but employs a slightly simpler strap system for attaching skis or a board. Basically, two straps encircle the pack and can be adapted to whatever you need to strap on. It's a panel-loader, so the entire pack opens up when you need to find stuff. In a nice touch, Arc'Teryx uses light-colored material in the lining, which can make it easier to find stuff on gloomy winter days. And it has pockets and slots for shovels, probes, and so on. One of the nicer ski-oriented packs out there, albeit a bit dear, money-wise.
For something a bit more economical, REI's Double Diamond pack offers a ski-friendly 2,100-cubic-inch pack for a reasonable $120. It has outside straps that accommodate skis or boards, a big back zipper for easy access to gear, and a wealth of compartments and lash-on points to handle all the stuff you need on a ski trip. Very nice pack.