[Epyon MX]

So I'm planning a backpacking trip in late August with a friend of mine (The weekend before PAX). We're still early in the planning stages, but we're thinking about a trip to a national park in WA. I've never been to the Pacific Northwest and it sounds amazing. Trouble is, I have no knowledge of the region. There are a few PGLers who are from Washington state. How many of you have been to one of the big parks (Olympia, Ranier or Cascades). Any recommendations or tips? 'ppreciate it!