Hadar (also spelled Qad daqar, Qadaqar; Afar "white [qidi] stream [daqar]") is a paleontological site in Mille district, Administrative Zone 1 of the Afar Region, Ethiopia, 15 km upstream (west) of the A1 road's bridge across the Awash River (Adayitu kebele). It is situated on the southern edge of the Afar Triangle (part of East Africa's Great Rift Valley), along the left banks of the Awash River, between two minor tributaries, the eponymous Kada Hadar and the Kada Gona. In 1972, Taieb organized a small exploratory reconnaissance of the Afar region to investigate more paleontological finds there. After six weeks of exploration, the party focused on the Hadar site. The site has yielded some of the most well-known hominin fossils, including "Lucy". These hominin fossils range in age from approximately 3.42 to 2.90 million years ago. These finds give us a greater understanding of hominin evolution during this period. It is postulated that the specimens in the region were deposited by way of a large river system with associated crevasse channels/splays, deltas, and distributary channels, as well as periodic transgressions of paleolake Hadar located east of the research area (Aronson and Taieb, 1981, Tiercelin, 1986, Campisano and Feibel, in press) possibly related to geological activity or climatic cycles in at least the Kada Hadar Member (Yemane et al., 1996, Yemane, 1997, Campisano and Feibel, in press)." According to Jon Kalb, early maps show caravan routes passing within 10 to 15 km of Hadar but not through it. The British explorer L.M. Nesbitt passed 15 km west of Hadar in 1928. Geology The region's rocks consist mainly of mudstones, siltstones, fine-grained sandstones and volcanic tuffs. The region has been divided into four geologic members—Hadar Formation, Basal (∼3.8–3.42 Ma), Sidi Hakoma (∼3.42–3.26 Ma), Denen Dora (∼3.26–3.2 Ma) and Kada Hadar (<∼3.2 Ma)—with three tuffs (Sidi Hakoma Tuff [SHT], Triple Tuff [TT] and Kada Hadar Tuff [KHT]) separating the four members. The Sidi Hakoma member tends towards high rainfall and low seasonality. The overlying Denan Dora Member was a grassland habitat. Finally, the Kada Hadar Member was an even more open and arid habitat, as seen in the high abundance of antilopines, which frequent these types of terrains. Paleontology The first paleo-geological explorations of the Hadar area were conducted by Maurice Taieb. He found Hadar in December 1970 by following the Ledi River, which originates in the highlands north of Bati to empty