How many Rangers of the North were there ?

[Morthoron]

Originally Posted by The Mouth of Sauron

When Halbarad and other Rangers caught up with Aragorn just beyong the Fords of Isen, Halbarad said that he had 30 Rangers with him, declaring : "that is all the brethren that could be gathered in haste".

That statement implies that there were others who couldn't be contacted in time. So how many Rangers of the North were there in total at the time of the War of the Ring and where were they based ?

I don't think Tolkien ever estimated the amount of Dunedain remaining in Eriador; however, one could surmise there were at least a few hundred to several hundred, including women, children, the infirmed and the elderly, scattered across what was Arnor. I would assume there were several clans, with Aragorn as their chieftain, stationed in strategic spots to guard what remained of their fractured kingdom. I say several hundred simply because from a modern, revisionist standpoint, the gene pool would have gotten mighty thin and abherrent with a very small number continually inbreeding over the centuries. I wonder how many toes Aragorn had?