Water should be number 1 on your list since you can only go like 3 days without water, especially in the summer months.
True, but only three HOURS in extreme cold or heat...
Fire/shelter should be your first priority.
Where I go hiking there is tons of water, rivers and streams that are formed from glacial run-off. All the way to the ranger station at the mouth of the canyon. So a small water purifier and a bottle would do you in that area.
