Joshua 13:8, 10, 24-28

The other half of Manasseh, the Reubenites and the Gadites had received the inheritance that Moses had given them east of the Jordan, as he, the servant of the LORD, had assigned it to them.

and all the towns of Sihon king of the Amorites, who ruled in Heshbon, out to the border of the Ammonites.

This is what Moses had given to the tribe of Gad, according to its clans: The territory of Jazer, all the towns of Gilead and half the Ammonite country as far as Aroer, near Rabbah; and from Heshbon to Ramath Mizpah and Betonim, and from Mahanaim to the territory of Debir; and in the valley, Beth Haram, Beth Nimrah, Sukkoth and Zaphon with the rest of the realm of Sihon king of Heshbon (the east side of the Jordan, the territory up to the end of the Sea of Galilee). These towns and their villages were the inheritance of the Gadites, according to their clans.