Regarding drones, don't get me wrong, I wasn't advocating flying in National Parks. I know that's clearly prohibited. What I meant was that at the places I visited in Arizona, it didn't prevent you still getting some good shots because you could fly just outside the perimeter of the restriction and still have cool landscapes and features to film and shoot. When I went to Monument Valley, there were "no drone" signs everywhere so I didn't fly... until I left the $20 circular track and drove north on the main road for 10 mins to the edge of the reservation where I could fly and still see some amazing colours and buttes. But places like Yellowstone etc. it doesn't look like you can drive to the edge of it and fly. You'd be driving a long way and you wouldn't be able to capture the iconic bits. I heard about the drone crashing into the Prismatic spring and yes, it's things like that which give rise to the bans and regulations. It's frustrating because I'm super careful with mine - I keep away from people and cars, don't get it into silly situations and generally err on the side of caution. I'd love to fly around the Prismatic spring and capture the colours from the air, but I can't, thanks to the idiots.
@ Homerjay - when I was at Monument Valley in late May, it was spectacular although I can't say it was a spiritual experience. But maybe that was due to the precautions I was having to take to avoid bottoming out my hired Mustang on the rough dirt road, and the various tourists who seem not to grasp the concept of a one-way road.
Thanks
Gardyloo for the list of places, certainly looks like plenty to do although most of the accommodation you linked to is already fulled booked on most days, which makes me concerned if I can't get accommodation here, let alone in a national park... I'm also wondering about the weather, how frequently is it likely to be cloudy/overcast or wet in Oregon and Washington? If I were to return to Seattle instead of Portland then I can fly back to the UK direct/non-stop - would there be much to see on a round-trip along the Columbia River and then head north-west back to Seattle?
Bit concerned too at the mention of the humidity in the north west states. It's the humidity that's the killer when I'm visiting our St Louis office in the summer. I think I'd prefer temps in the high 30s in the bone dry desert heat, rather than lower temps in humidity!
I need to look more at options of Glacier NP and Banff. Not sure how I'd get to Glacier, from STL? Being up in Montana, is it quieter than the other National Parks, or is it still likely to be packed in various places? Do I need to be worried about bears in such places or is it really just a case of using common sense?