The Yarmuk River is located on the southern edge of the Golan Heights. To the south of the Yarmuk is the modern country of Jordan.
This is a very powerful river that flows into the southern Jordan River just south of the Sea of Galilee. Much of its water does not reach the Jordan River for the Hashemite Kingdom of Jordan has diverted most of it for irrigation purposes.
Zondervan Atlas of the Bible p. 34.