Buy the best pack you can afford...
ou will use an internal or external frame pack. External frames are cheaper and will work. Internal frames are more comfortable and quieter for hunting (my preference), especially when hunting in the brush or cliffs for goats and sheep.
You will need at least a 4500 cubic inch external or a 5000-7000 cubic inch internal. If you bring an external pack, get one with a built in sleeping bag compartment. In that case, you will want one that holds at least 5,000-6,000 cubic inches also. Put your backpack (if external type) in a large duffel for the commercial flight as it will be less likely to get damaged by the airlines.
When packing, put the lightest items at the bottom of the pack. Pack the heavy items near your shoulder blade/lower neck level and close to your body. It is better to have a big pack and cinch it up close to your body than to use a small pack and have it barrel out with too much gear.
Barney’s Sport Chalet sells the best external frame packs for hunters. I like their Pinnacle model. Dana Designs, Alaska Gear, Kelty, Gregory, Cabela’s and Camp Trails will all work. The Canadian made Wilderness Wanderer is big and well made, but heavier.
The best internal frame packs I’ve seen are made by Mystery Ranch. This is what our guides and myself use. We use the a 6-7000 Nice Frame. Most hunters would be fine with the 6000. They come in Coyote, Foliage or multicam, and although designed previously for mountaineering, they now have excellent pocket and strap design for the hunting application. They fit and adjust easy for many different users. I would recommend this pack for sheep hunts.
Cheap packs will run $150-250, but you get what you pay for. Make sure you get an extra waist belt buckle and chest strap buckle (these should be left in your pack at all times). If you have an aluminum-framed pack, you should pack several extra pins/rings. I also like to have a couple 2-3 foot long, 1” wide nylon straps with buckles for tying on loads and antlers.A pack/fly rain cover is a necessity.