This is a "must see".
I was there in August of last year, and was impressed. I MISSED the engine house (it is a bit removed from the mine, and I don't remember a sign) but there is a lot to see. Most impressive is the hoist house and hoist engine. It is amazing that it survived without meeting the torch at some point.
The mine tour was very impressive... and it is hard to imagine the shaft was 9000 feet!!