Mount Ephraim (Hebrew: הר אפרים), or alternatively Mount of Ephraim, was the historical name for the central mountainous district of Israel once occupied by the Tribe of Ephraim (Joshua 17:15; 19:50; 20:7), extending from Bethel to the plain of Jezreel. In Joshua's time (Joshua 17:18), approximately sometime between the 18th century BCE and the 13th century BCE, these hills were densely wooded. They were intersected by well-watered, fertile valleys, referred to in Jeremiah 50:19.
Later, the region became known as Samaria, after the capital city of the northern Kingdom of Israel which was centered in the area.