Exploring this river in the mid-1890s and from interviews with local inhabitants, Alexander Bulatovich asserted that downstream of its junction with the Angar, the Didessa is rapid-free and potentially navigable.

[2] The early 20th-century explorer Herbert Weld Blundell opined that "Didessa" appears to have replaced a much older name for this river, finding no earlier usage for it "before 1861, when d'Abbadie was travelling in Western Shoa and made inquiries.

"[4] He also notes that at the confluence of the Didessa and the Abay, "the serious work of goldwashing begins, and continues along the Nile and down the course of the Dabus and its tributaries," adding that: The deep erosion of the upper strata of basalt and trap, and subsequent decomposition, lays bare the gneissic and hornblendic schist formations below, so that nearly the whole country from the foot of Chochi to the river, a distance of 15 miles, is covered with quartz pebbles and boulders, and shows numerous outcrops.

[5]Despite the efforts of these explorers, and the presence of humans in the area since roughly the origins of the species, the course of the Didessa from its point near Nekemte to its confluence with the Abay apparently was only traced in 1935 by Dunlop and Taylor.

He emphasized the difficulties which we would encounter: no paths, thick bamboo forests, fever, and, with an expressive upward wave of his hand, the steepness of the mountains bordering the river.