The Ouachita River begins in the Ouachita Mountains near Mena, Arkansas. It flows east into Lake Ouachita, a reservoir created by Blakely Mountain Dam. The North Fork and South Fork of the Ouachita flow into Lake Ouachita to join the main stream. Portions of the river in this region flow through the Ouachita National Forest. From the lake, the Ouachita flows south into Lake Hamilton, a reservoir created by Carpenter Dam, named after Flavius Josephus Carpenter. The city of Hot Springs lies on the north side of Lake Hamilton. Another reservoir, Lake Catherine, impounds the Ouachita just below Lake Hamilton. Below Lake Catherine, the river flows free through most of the rest of Arkansas.