Refrigerator,
You are talking about one of the great backpacking trips in North America. I love "the Mountain" and have spent plenty of time there. I spent a summer down the road near Eatonville, WA. It is one of the best places to see wildflowers, mtn goats and views of Mt Rainier.
The one caveat is the weather. It is usually wet. Wet in ways most people have not experienced. This summer would have been the perfect year to go with all the clear days and strong high pressure for weeks on end. The PNW on a clear day cannot be beat. On the other hand, I have been on backpacking trips in the Cascades to lakes and never seen them due to the fog and rain. Wonderland requires advance planning. You are at the mercy of the weather. Besides the obvious like new raingear, bring extra stove fuel, a free standing tarp, and 5 kinds of fire starters. Good luck.
