Answer
Mount Ephraim is mentioned over 30 times in the King James Version. It is not a specific mountain but rather the hilly or mountainous region within Ephraim’s territory. While people typically distinguish between mountains and hills based on size, there is no clear criteria that differentiates the two. The terms “hill” and “mountain” are relative and can be used interchangeably when describing the geography of the area.
Most contemporary translations refer to it as the hill country of Ephraim or occasionally the mountains of Ephraim. Even the King James Version itself indicates that Mount Ephraim is not a singular mountain but a mountainous or hilly region: “And Abijah stood up upon mount Zemaraim, which is in mount Ephraim, and said, Hear me, thou Jeroboam, and all Israel” «And Abijah stood up upon mount Zemaraim, which is in mount Ephraim, and said, Hear me, thou Jeroboam, and all Israel; », (2 Chronicles 13:4). To consider Mount Ephraim as a single mountain, one would have to envision Mount Zemaraim being located on or within Mount Ephraim. Similarly, for 2 Chronicles 15:8 to make sense, one would have to picture a single mountain with multiple cities on it: “And when Asa heard these words, and the prophecy of Oded the prophet, he took courage, and put away the abominable idols out of all the land of Judah and Benjamin, and out of the cities which he had taken from mount Ephraim, and renewed the altar of the Lord, that was before the porch of the Lord.”
Approximately half of the territory belonging to the tribe of Ephraim consisted of hilly or mountainous regions, while the other half was flatter, closer to the coastal plains. In Joshua 19:50, Joshua, who was from the tribe of Ephraim, was given a city in the hill country of Ephraim as his inheritance. He was later buried there «And Eleazar the son of Aaron died; and they buried him in a hill that pertaineIn Judges, much of the action takes place in the hill country of Ephraim. Ehud (a Benjamite) rallied the people for battle in the hill country of Ephraim, which bordered the territory of Benjamin «And it came to pass, when he was come, that he blew a trumpet in the mountain of Ephraim, and the children of Israel went down with him from the mount, and he before them. », (Judges 3:27). Deborah, of the tribe of Ephraim, lived in the hill country «And she dwelt under the palm tree of Deborah between Ramah and Beth-el in mount Ephraim: and the children of Israel came up to her for judgment. », (Judges 4:5). Gideon later rallied troops from the mountains of Ephraim «And Gideon sent messengers throughout all mount Ephraim, saying, Come down against the Midianites, and take before them the waters unto Beth-barah and Jordan. Then all the men of Ephraim gathered themselves together, and took the waters unto Beth-barah and Jordan. », (Judges 7:24). Abimelech, a lesser-known figure, was made king in Shechem, a city of refuge in the hill country of Ephraim «And Abimelech the son of Jerubbaal went to Shechem unto his mother’s brethren, and communed with them, and with all the family of the house of his mother’s father, saying, », (Judges 9:1).In Judges, Tola, a man of Issachar, lived in Shamir in Mount Ephraim after Abimelech «And after Abimelech there arose to defend Israel Tola the son of Puah, the son of Dodo, a man of Issachar; and he dwelt in Shamir in Mount Ephraim. », (Judges 10:1). The events in Judges 18—19 also took place in the same region of Mount Ephraim.
Saul looked for his lost donkeys in the hill country of Ephraim «And he passed through Mount Ephraim, and passed through the land of Shalisha, but they found them not: then they passed through the land of Shalim, and there they were not: and he passed through the land of the Benjamites, but they found them not. », (1 Samuel 9:4), and some Israelite men hid from the Philistines there «Likewise all the men of Israel which had hid themselves in Mount Ephraim, when they heard that the Philistines fled, even they also followed hard after them in the battle. », (1 Samuel 14:22). Sheba, who supported Absalom against King David, was also from the hill country «The matter is not so: but a man of Mount Ephraim, Sheba the son of Bichri by name, hath lifted up his hand against the king, even against David: deliver him only, and I will depart from the city. And the woman said unto Joab, Behold, his head shall be thrown to thee over the wall. », (2 Samuel 20:21).
After the division of Israel into the northern (Israel) and southern (Judah) kingdoms, Ephraim was located on the southern border of the northern kingdom. King Jeroboam established the city of Shechem in the hill country as one of his royal residences «Then Jeroboam built Shechem in Mount Ephraim, and dwelt therein; and went out from thence, and built Penuel. », (Judges 10:1).(1 Kings 12:25). Since it was on the border between the northern and southern kingdoms, some of the territory passed back and forth, as in 2 Chronicles 15:8.
In Jeremiah 4:15, Dan and “mount Ephraim” are mentioned because they represent the northernmost and southernmost boundaries of the northern kingdom of Israel: “A voice is announcing from Dan, proclaiming disaster from the hills of Ephraim.” In other words, judgment is coming on the land “from top to bottom.” However, Jeremiah also promises that the Lord will redeem His people: “There will be a day when watchmen cry out on the hills of Ephraim, ‘Come, let us go up to Zion, to the LORD our God’” «For there shall be a day, that the watchmen upon the mount Ephraim shall cry, Arise ye, and let us go up to Zion unto the LORD our God. », (Jeremiah 31:6). “But I will bring Israel back to their own pasture, and they will graze on Carmel and Bashan; their appetite will be satisfied on the hills of Ephraim and Gilead” «And I will bring Israel again to his habitation, and he shall feed on Carmel and Bashan, and his soul shall be satisfied upon mount Ephraim and Gilead. », (Jeremiah 50:19).
Although not specifically referred to in the New Testament, most of the hill country of Ephraim would have been in Samaritan territory.