Face it – there's just way too much to do in the Northwest. Rather than spreading yourself too thin, I would concentrate on one or two areas. Frankly, you can't go wrong. What sorts of activities do you enjoy – hiking, perhaps?
In any event, don't bother with Mount Rainier – it's got a lot of this ugly cold white stuff all over it:
Seriously, we spent two weeks at Rainier during the summer of 2010, just hiking to our heart's content. We spent a month in Northern Washington (the Cascades and the Olympics) in September 2014. We spent a month in the Canadian Rockies in September 2012. Take your pick! And once you focus on a specific area, let us know, and I'm sure we will all chime in with suggestions for recreational possibilities.
