Mareka Gena was one of the 77 woredas in the Southern Nations, Nationalities, and Peoples' Region of Ethiopia. Part of the Semien Omo Zone, Mareka Gena was a triangle-shaped area located south of the confluence of the Omo River and its east-flowing tributary the Gojeb River, bordered on the southeast by Loma Bosa, on the west by Isara Tocha, and on the north by the Oromia Region. Towns in Mareka Gena included Wacca and Weldehane. Mareka Gena was divided for Gena Bosa and Mareka woredas.