If you're thinking of hiking a long stretch (maybe even the whole) of your local trail, then you're definitely going to need the backpack that does the business. These backpacks are designed to carry everything you need if you plan to be away from the creature comforts of home for a week or more and have more compartments than you can shake a stick at.
Gregory Mt. Products Baltoro 75 Backpack GM57911
Gregory Mt. Products Womens Deva 70 Backpack GM59695