'Hill country' in the Bible

Now there was a certain man of Ramathaim, a Zuphite of the hill-country of Ephraim, named Elkanah; he was the son of Jeroham, the son of Elihu, the son of Tohu, the son of Zuph, an Ephraimite:

So they went through the hill-country of Ephraim and through the land of Shalishah, but they saw no sign of them: then they went through the land of Shaalim, but they were not there: and they went through the land of the Benjamites, but they did not come across them.

And all the men of Israel who had taken cover in the hill-country of Ephraim, hearing that the Philistines had been put to flight, went after them, attacking them.

And all the people were with Saul, about twenty thousand men, and the fight was general through all the hill-country of Ephraim; but Saul made a great error that day, by putting the people under an oath, saying, Let that man be cursed who takes food before evening comes and I have given punishment to those who are against me. So the people had not a taste of food.

And David kept in the waste land, in safe places, waiting in the hill-country in the waste land of Ziph. And Saul was searching for him every day, but God did not give him up into his hands