What does Joshua 13:27 mean?

In the valley, their land included Beth-haram, Beth-nimrah, Succoth, and Zaphon—the rest of the kingdom of Sihon, king of Heshbon. The Jordan River was their western border, up to the Sea of Galilee, east of the Jordan. Joshua 13:27 - Modern Text Bible

(Gad’s land included more towns in the valley, with the Jordan River as the western edge, reaching up to the Sea of Galilee.)