While out exploring this area just past the dog park a while back, after passing a beached boat, I headed further south through the tall grasses and saw a wooded area just to the west of the path. I decided to check it out, and noticed it to be a bit creepy, so I came back and decided to hide a cache there.
You can park at the dog park (parking coordinates attached) and will need a NW Forest Pass to park here. Enjoy the walk along the water line.