Haldor location help

I have been looking for Haldor for several hours on my world, I know that he has 10 possible spawn locations on a given seed and that once he spawns at one of those 10 he stays there permanently. I am wondering if there is a chance he has spawned at one of these locations I have passed but I haven’t come close enough for the icon to appear on the map, is this possible or do they have the same range?