There are going to be a few free-entry days to US National Parks in 2017. It's the 100th Anniversary of the NP system, so they've expanded the free days somewhat. Here's a URL for the list (but we've already missed the first one): https://www.nps.gov/planyourvisit/fee-free-parks.htm
It looks like the BMW MOA Fontana Dam Getaway weekend occurs during one of these. I think that means that the most popular park in the NP system (Great Smoky Mountains) will draw more people to the area of the Fontana Getaway. Yikes!