American Plunge is a flume ride in Hugo's Hill Street at Silver Dollar City. While it's not a "must do," it is also recommended. The minimum height to ride is 34 inches.
The American Plunge is an Arrow log flume with a few animatronic set pieces and a long, dark tunnel along the way (the tunnel used to be nicely themed, now, sadly, it is just a dark tunnel). The finale is the requisite 50-foot plunge to a splashdown.