The Tamasheq language is spoken principally in an area located 20 km north of what river?
Tamasheq language:  It is spoken by the Tuareg people, principally in the Timbuktu area. Timbuktu: Timbuktu (pron.: ), also spelled as Tinbuktu, Timbuctoo and Timbuktoo (Berber: ;French: "Tombouctou" ; Koyra Chiini: "Tumbutu"), is an ancient city in Mali, situated 20 km north of the Niger River.
Niger River