I believe they are open all year
Yes, it is open all year. Go to their website for adjusted times for holidays.
They are open all year, closed on Thanksgiving and Christmas day. Check their website for up to date information.
Closed Thanksgiving and Christmas (Day & Eve)
They're open all year (they say the cave is a cool 60° in the summer, a warm 60° in winter), but they're only open until 4pm Nov through Feb. (Closed Thanksgiving, Christmas eve, and Christmas day.)
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