Last month, my girlfriend and I did Washington Section J (Snoqualmie Pass to Stevens Pass), and it was not only breathtakingly stunning, but there were also thousands of options for hanging. In fact, observing how much easier a hammock would have made camping there was one of the things that led me to these forums.
Check out this guy's TR, complete with incredible photos:
Since most of the trail in that section is switchback, conventional tenting/tarping is a challenge. Appropriately flat sites are few and far between; on several days we had to push on 4-6 miles beyond our intended destination because there were virtually no level spots for my Tarptent Squall 2. With a hammock in my pack, however, I would have had countless options, what with the endless Ponderosa pines out there. One thing to consider, though, is that you would absolutely need a bug net. The skeeters out there are some of the most hellacious I've ever encountered, and they do not stop at nightfall.