Why is northern Eriador (Lake Evendim, Fornost) deserted at the end of the 3rd Age?

[CSteefel]

Originally Posted by Inziladun

I think it was a gradual happening, occurring for the reason you give, and also because many of the Dúnedain of Arthedain had perished in the long-term fighting. With so many gone, perhaps Annumínas was already falling into decay, even as Minas Tirith was later observed to be when Pippin went there with Gandalf.
I see another parallel with the abandonment of Osgiliath, the location of the King's House in Gondor, and the removal thereof to Minas Anor at about the same time.

I think the comparison with Osgiliath is pretty good, and reinforces some of the comments above about the idea that Annuminas was probably not as easily defensible as Fornost.

Anyway, repeating myself to some extent, the comments that the "Rangers go there sometimes" suggests that they do NOT live to the north, but probably closer to the Angle as suggested elsewhere. I am not sure that 1,000 or more makes sense for the Rangers, given that they could only muster on the order of 30 or so men for the final battles. The largest contingent of Rangers seems to be somewhere in the vicinity of Sarn Ford, since the Unfinished Tales tells us that there was at least a modest force there who were driven off by the Nazgul.