town, southeastern Mali, West Africa, on the Niger River. It is a mining (antimony) and agricultural (grains, livestock) marketing centre. Prospecting for uranium began in the late 1970s. The Niger is navigable for about 1,000 miles (1,600 km) above Ansongo. Directly to the east is the Ansongo-Ménaka animal reserve, which covers an area of more than 4,300,000 acres (1,750,000 hectares). Pop. (latest est.) 3,483.