The Šaška river, the longer headstream (17 km), originates from the northern slopes of the Liškovac mountain, under the mountain's highest peak, Veliki Liškovac, east of the town of Majdanpek. The river flows to the south, curving around the western side of the Liškovac mountain and the northern slopes of the Mali Krš mountain, next to the oldest copper mine in Europe and once prosperous mining village of Rudna Glava. It meets the Crnajka in the narrow valley between the southern Liškovac and northern Deli Jovan mountains, at the village of Miloševa Kula, forming the Porečka river.