Drâa River, intermittent stream (wadi) of southern Morocco. Rising from two headstreams, Dadès and Imini, in the High Atlas (Haut Atlas) mountains of central Morocco, it flows southeastward to Tagounit, hence it courses southwestward, forming much of the Algerian-Moroccan frontier, to the Atlantic near Cap Drâa. Of its total length of 700 miles (1,100 km), the longest of any Moroccan river, all but the headstreams and upper course are usually dry. Ouarzazate and Zagora are important riverine oases.