The Jordan Valley
In the Madaba Map the mountains Ebal and Garizim are shown twice, once near Galgala, in the Jericho region, and once near Nablus. The mosaicist was well aware of the existence of two traditions: the Samaritan and the Jewish one (followed also by the Christians) and, apparently, choose not to choose between them. See no. 43.
14. Gerizim - (Mount Gerizim)
The reference to Gilgal in Deut 11:30 remains enigmatic. The preceding verse gives the distinct impression that reference is being made to a location somewhere in the vicinity of Mount Ebal and Mount Gerazim, that is, near ancient Shechem. This is further strengthened by the reference to the Oak of Moreh, which Gen 12:6 clearly locates at Shechem. Thus, it seems that an as yet unidentified location somewhere in the vicinity of Shechem also bore the name Gilgal. Perhaps this is the same Gilgal as that known to Elijah and Elisha. However, many scholars feel that the overall context of this verse, referring as it does to entrance into the promised land, requires that Gilgal near Jericho be the point of reference. One provocative idea relates these verses in Deuteronomy to a rabbinic tradition suggesting that the Israelites utilized artificial heaps of stone as replicas of Ebal and Gerazim as part of a cultic celebration at the more famous Gilgal (Brownlee ISBE 2: 471).
Wade R. Kotter, The Anchor Bible Dictionary, ad v. "Gilgal (Biblical Place)" (extract)
Michael Avi-Yonah (The Madaba Mosaic Map, Jerusalem 1954, 47)
Ebal. Gerizim. In Placing these mountains near Jericho the mosaicist followed Rabbinical tradition (Sifré Deut. 56 etc.) taken up by Eusebius (On. 64,10), Epiphanius (De xii gemmis, PG 43,362; id. Adv. haer., IX,2, ib. 41, c. 225), Procopius of Gaza (Comm. in Deuteronom., PG 87, 905f.). For the better tradition of the Samaritans see nos. 42-43)
Map Section 2 Place Sources