Both rivers originate from Anatolia and are fed by numerous tributaries; the entire river system drains a vast mountainous region. In the western Levant, hilly terrains and mountain ranges rise parallel to the Mediterranean coastline from the north to the south encompassing the: An-Nusayriyah Mountains, Lebanon Mountains, Galilee Hills, Samarian Hills, and Judaean Mountains. This mountainous barrier receives a substantial amount of precipitation and snow, and enjoys a thick forest cover, mainly Mediterranean woodlands and forests.