Its open, check on visitors center hours, sure it would be rough going with all the snow, trails aren't cleared. But some good viewing if you're up to it. Skis or snow shoes???
While it is open I'm not sure on that current state of the walk ways as they aren't cleared, they may be packed down by other people walking or sking the paths.
It is open in winter, but the paths are not shoveled to allow casual walking. You're pretty much on your own. A lot of people walk and even ski on the trails, I walked it a couple weeks ago and got a decent workout.
Not sure about off season! Right now, there's lots of snow. The best times would probably be spring and fall.
The trails are open and it is a wonderful time to spot owls and seals and winter birds! Check the hours of the visitors center for the off season, though.
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