$7 per person
I think it was $5 or $7 per person.
Inside the museum im not sure but there is stuff outside that is free such as one of the mineshafts
it's worth noting that if you're a qualifying senior, you can buy a year pass that gets you into all state parks for free. definitely the best deal. (not that I'm implying anything about your age...)
Not much it's been awhile since I've been there and it was just a donation of a dollar I think
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