Burkina Faso consists for the most part of a vast lateritic plateau in the West African savanna, approximately 198–305 m (650– 1,000 ft) above sea level. The highest point (749 m/2,457 ft) of Téna Kourou is near the Mali border, southwest of Orodara. The land is slightly inclined toward the south and notched by valleys formed by the three principal rivers, the Black, White, and Red Voltas, and their main tributary, the Sourou. They are alternately dry or in flood and all are unnavigable. In general, the land is dry and poor.