Finding hammock trees in the PNW can be a challenge but its not always only big trees. Even on the PCT, the Alpine Lakes, etc., you can usually find at least one tree for an easy wrap. But, if using webbing, at least 12' is a good idea.
My last weeklong in the Olympics was without a hammock but then the problem was in finding a branch low enough to fling a bear bag rope over. And be sure, if you spend time in the Olympics, you will encounter black bear.
Last weekend (4 days) was spent in the NW corner of Mt. Rainier NP where the bugs were still a nuisance and temps dropped into the low 30s. But double-wrappable trees were in abundance.
Having lived in the area for over 30 years, I now look forward to Labor Day weekend--afterwards, the crowds thin out dramatically, particularly mid-week and by then the bugs are gone, but there is still enough daylight to get in some miles. If you plan to hike on the west side of the Cascades, September is still pretty dry (relative to normal Seattle weather). East side of the Olympics will be even drier and east of the Cascades the driest.
If your intent is to avoid crowds, then the suggestion is probably similar to anywhere else: go mid-week and go beyond day-hike limits into the wilderness.
Except for one planned hammock hike (with BrianLe), I have yet to encounter another backpacker, or even car camper for that matter, using a hammock for sleeping (some car campers put them out for day use). So, every trip is an opportunity to evangelize. Sort of ironic with Hennessey just north of here.
Good luck on your trip and report back what you learn.
I've been reading this thread with interest. Some time before January, we'll be trading Minneapolis for Ashland Oregon. Aside from the small problem of my not being able to find employment in my field (electrical engineering), I'm really looking forward to relocating closer to what looks to be amazing geography.
Of course, where I'm going to put my hammock has been the most important concern on my mind. Selling my house, finding a job, finding a school for my daughter, moving, finding a new place, etc. is really secondary.
Oh boy, are you in for a change in "geography", especially regarding the vertical aspect! I've been there enough ( as a ground dwelling backpacker and day hiker) to know that, because of the vast forests of the PNW, hammocking spots should be super abundant. The only trick for a hammocker is, if coming there as a visitor instead of being local who knows the area, to not pick a trail that is mostly above tree line and to not pick a place that has ONLY super gigantic trees- if there even is such a place. In between will be billions of normal trees. And some of the most spectacular landscapes in the world, IMO. And if all that is not enough for you, you are really not all that far from the Canadian Rockies and coast range.
What, are you just moving on a whim? I'm jealous! But we all know that your primary concern over where you might hang your hammock is fully rational!
My wife, a professional actor, has accepted a year contract with the Ashland Shakespeare festival. It is a big deal in the acting world and it was something she just couldn't pass up. I'm going because our marraige wouldn't survive the long distance, and it isn't as though I love my current job anyway. I wouldn't mind working in my field at a different company, however. The problem is that there is nothing within commuting distance. So I'm going to do something else. I haven't a clue what it is though. Perhaps I'll write the next great novel. Or perhaps I'll sit on my couch all day until I can go camping on the weekends.
"Except for one planned hammock hike (with BrianLe), I have yet to encounter another backpacker, or even car camper for that matter, using a hammock for sleeping "
Oh, you're that Scott --- Hello! Yes, I'm back to using the hammock sometimes again; for me it boils down to there being no perfect sleep system (for me at least).
In terms of finding good trees for hanging, one phenomenon I've encountered is where there are trees everywhere but no good trees to hang from --- in particular, when you get a planted forest with understory branches that just preclude hammock use. So just seeing a ton of trees isn't a guarantee. Still, it's almost always easier to find a place to hang than to find a sufficiently flat and level cleared space for a tent !
However, I agree that, in most of the places I am talking about, which are not at a designated campground, it would be even harder to find a good spot for a ground dweller. Because you would still have the poison ivy problem, plus roots, rocks, uneven ground, insects and snakes.
It just that it takes a lot longer than you might think to find a hammocking spot even though you are in the middle endless trees. But in a similar forest without so much poison ivy, it would be about 10 times quicker to find a good hanging spot.