The Old Stone Fort is located on a peninsula created by the confluence of the Duck River and the Little Duck River (the section of the Duck River upstream from its confluence with the Little Duck is sometimes called "Barren Fork"). The Duck River system spills over a limestone-rich shelf of the western Cumberland Plateau known as the Highland Rim. As the Duck and Little Duck approach their convergence, they rapidly drop in elevation, and have cut relatively deep gorges around the peninsula upon which the Park is located.
The first people to have run this in kayaks are Justin Owen and Steven Wright. I originally found out about this run because of a post on a blog at Jackson Kayak by Justin found here:
http://jacksonkayak.com/blog/2011/01/24/justin-owens-duck-river-drops/ .
Everything can be scouted from the trail on river left, there is no reason to not scout these drops before you boat. Quite a few of these drops land on rock shelf and it is recomended that you come at low water to scout the rock so you know where to run.These rapids come and go at different water levels, but Big Falls has been run down to 300cfs and still goes. It is a bit of a hit at this level. At higher levels there become several low head dams and should be avoided unless you are feeling luckly. It is completely non commiting and is a very good park and huck that does not take a bunch of time.