That聮s a straightforward question, but of course there are a few variables to the answer. It depends on the type of trip you聮re planning聴guided, or un-guided聴and what time of year.
Kelty Tornado 4900
Tornado 4900 backpackLet聮s say you聮re doing the normal routine: Paradise Lodge to Camp Muir, a night at Muir, then on to the summit the next day, and then back out to Paradise. That is a trip you will not forget, at least not until the pain in your thighs subsides, and that could take weeks. I cannot emphasize enough the sheer brutality of such a trip. It聮s not getting up the thing聴something most reasonably fit people can manage聴it聮s coming all the way down the same day.
But I digress. For that trip you聮re carrying clothing, sleeping bag, probably half a tent (assuming you’re with someone), cooking kit, etc. You聮ll need at least 4,500 cubic inches in most cases, and maybe 5,000. That would be a pack such as Gregory聮s Lassen (4,525 cubic inches, $319; www.gregorypacks.com), Osprey Crescent 85 (5,100 cubic inches, $379; www.osperypacks.com), or Kelty Tornado 4900 (4,900 cubic inches, $180; www.kelty.com). You don聮t need a 聯summit pack”聴just carry the mostly empty big pack top the top. And all of these packs have good suspensions (pay more, get a better one), plenty of tie-on points for ropes and crampons, and good volume.
On the other hand, let聮s say you聮re climbing in July or August (this could apply for Scenario One as well). The weather forecast is benign (caveat: never assume good weather on Rainier), and you聮re either on a guided trip and will be sleeping in a hut or using the public climbing hut at Camp Muir (recently remodeled and, for now, mouse-free). Let聮s say as well that you聮re packing modern, lightweight rain shell and pants (Patagonia Stash jacket, $225, and Rain Shadow Pants, $80; www.patagonia.com), maybe a soft shell jacket (Arc聮Teryx Gamma SV, $259; www.arcteryx.com), light down-filled 30-degree sleeping bag (Marmot Arroyo, $249; www.marmot.com), etc. Then you might not have more than 4,000 cubic inches worth of stuff, and you could haul a lightweight pack such as REI聮s Cruise UL 60 ($130; www.rei.com), which has just under 4,000 cubic inches of capacity in a package that weighs only three pounds, two ounces.
Hope you have a great trip! Luckily for you, there聮s lots of good, steep day hikes in your area for training. Oh, wait, you live in Michigan! So I guess it聮s a Stairmaster for you, pal.
You聮ve got your winter gear, now get outside and use it. makes it easy to find nearby slopes just begging for fresh tracks.