I've lived in Washington State all my life (which is a long time). I grew up mostly in Seattle. I live south of Seattle now. Closest to me is what we used to call the "Nisqually Wildlife Refuge" and now called the "Billy Frank Jr. National Wildlife Refuge".

I might be able to help if you define "Seattle area", what kind of wildlife you are looking for, your physical capabilities, the gear you have, what you have for transportation and how far you can travel from Seattle.