Could you survive living in the wilderness in western Washington state?

I am looking to go out into the wilderness for 1-3 years, and I was wondering if the Cascade or Olympic mountains of Washington state would be a good choice, the climate is pretty moderate there, and as far as I know there are no extraordinarily dangerous diseases or organisms there. I will definitely bring supplies like tools to build a shelter, books, maybe some entertainment, first aid, etc. I was wondering if I should stay in a trailer, RV, camper, or a tent, or just build a shelter myself. I'm not sure about building something myself because I'm not what you would call a handyman.