Dairycreek. I would most certainly go with the 45-70, as it will handle much heavier bullets. You might have to handload to get the power you need as the factories must load their ammo to be safe in the weakest of rifles. If you don't reload, you might find someone who does it commecially.
I have seen some of Western Oregon's country, and have personally hunted the rain forests of Washinton state's Olympic Penninsula, specifically in the Humptulips area.
The big problem with the .444 Marlin is lack of bullet weight, unless you reload. With the 45-70, I believe Remington still loads the 400 grain bullet, which is what you want (need) for elk. While I will not give out personal loading data, I can recommend sources that you can access.
Of course you realize both cartridges are relatively short range propositions, that might not be suitable, should you decide to hunt in clearcuts.
If you wish to discuss it further, please don't hesitate to E-mail me. I'll be more than glad to try and answer your questions.
Paul B.
COMPROMISE IS NOT AN OPTION!
