Gregory Zulu 55

Backcountry.com says:
Whether we're backpacking through the Wind River range or doing a quick overnighter closer to home, the Gregory Zulu 55 Backpack will carry all the gear we need while keeping our back cool and comfortable every step of the way. The ventilated back panel has been specifically designed to allow air to pass between our back and the pack, and the spring steel wire frame comfortably supports up to 40-pound loads. We like the adjustable torso length and the separate sleeping bag compartment to dial in our fit and make the most of our packing space. Packing and organizing gear in the Zulu is made easy with the top access under the floating top pocket, plus a front U-zip access panel and bottom sleeping bag compartment. The front stash pocket provides an ideal spot to stash rain layers, maps, and whatever else we need to access quickly while the side pockets and hip belt pockets also give us easy access to small essentials. That's all we need for a backpacking weekend to recharge and reconnect with our natural surroundings.