The river flows through the Ouachita National Forest and then in a generally southerly direction until it empties into Gillham Lake.

The Cossatot is known as a difficult (class II - IV+) whitewater stream to canoeists and kayakers and a section at Cossatot Falls in Howard County, Arkansas has been called "the most challenging section of whitewater between the Smokies and the Rockies," though there are many more challenging runs in the state of Arkansas, such as Richland Creek, Crooked Creek or the Upper Buffalo (Hailstone run).

Cossatot Falls is a series of back-to-back class III-IV+ rapids that drops around 40 feet in 1/8 of a mile.

At certain higher levels near flood state, almost all of the Cossatot Falls turn into one long rapid.

The World War II fleet oiler USS Cossatot (AO-77) is named after this river.