Cagles Mill Lake: The control tower is round and the outlet works conduit was mined through solid rock. Cataract Falls, with upper and lower falls, is the largest waterfall (by volume) in Indiana. The lower falls ends at the headwater of the lake and is accessible by boat. The Corps' Tailwater Areas and much of the operational area around the dam have been designated by the Indiana Department of Natural Resources as a State of Indiana Natural Area.