There is nothing and/or no one stopping you from walking in. I was at rockport park the other day and did not see any park officials.
Yes, the parking area is open, a restroom building, informational signs, and usually a ranger around. Also they schedule ranger led hike/talk about the forest. You need a Discover Pass if staying more than 15 minutes.
It's fine to walk and picnic; just practice social distancing and wear a mask.
There are guidebooks on the service road in the old campground just like on the trails. It's okay to walk there.
The trails through the park are open. My family actually hiked the Evergreen loop just last weekend, and it was beautiful.
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