No, but they are required in closed public spaces like the restrooms.
Not the night I went.
Signs are posted, so bring 1, but we didn't wear them after entry. Had to have on for security wand scan.
When I was there on July 10 they were not, but given the changing guidance from the CDC I would strongly suggest that you reach out to Wolf Trap directly on the day.
No.
I am not sure if they are required, but it's open air.
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