John Gill Commentary Joshua 11:17

"from mount Halak, that goeth up to Seir, even unto Baal-gad in the valley of Lebanon under mount Hermon: and all their kings he took, and smote them, and put them to death." — Joshua 11:17 (ASV)

[Even] from the mount Halak, that goes up to Seir
Or the "smooth" and "bald" mountain, which had no trees on it, as some interpret it, observed by Kimchi; it was a mount on the borders of Edom, to which the land of Canaan reached on that side:

even unto Baalgad, in the valley of Lebanon, under Mount Hermon ;
and so describes the northern part of the land conquered by Joshua:

and all their kings he took, and smote them, and slew them ;
both in the southern and northern parts of the land.