We use our Golite 50L packs for trips up to a week or more...but the packs do have some straps that allow you to compress them for a smaller load. And they fit us well, so we sometimes use them instead of a daypack, when we are hiking with a couple of jackets and other stuff...
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Check our our website: http://www.backpackthesierra.com/

Or just read a good mystery novel set in the Sierra; https://www.amazon.com/Danger-Falling-Rocks-Paul-Wagner/dp/0984884963