I visited this mill site on Columbus Day 2008 and thought it was a free weekend so I was unprepared for the $10 tour charge. (There is no notation anywhere on any of their websites that there IS a fee or what it costs). I did not take the tour but wandered around the grounds and enjoyed looking in the windows.
When I returned home and read the two reviews, one mentioning a film at the visitor's center, I was disappointed that the young girl at the ticket desk/gift shop had not bothered to alert me that there even was a film there.
You have no recent hotel searches.