Grey Screes and Ling Scar are two spurs leading off from the summit of Kanchenjunga, and are mentioned frequently in Pigeon Post.

The prospectors comb Right across the Topps to the foot of Grey Screes and back again. Strip by strip .... like lawn-mowing (PP10)

Squashy Hat is above the prospectors on the steep slopes of Grey Screes while they comb High Topps (PP12) for the mine.

When they first see one of "Squashy Hat's" three patches of white paint, there seems to be no reason for it at all, and Dick thinks that the brown, reddish and black stuff looking like rust and ashes may be Iron. He wonders whether it may be the same crack going all the way up the hill: Dick had come very near the truth, but none of them knew it .... (PP18). Later though they realise suddenly that the white paint spots with which he has marked appearances of gosson on the slope are like leading lights .... pointing exactly here, that is to the Gulch (PP22). This is because the occurences of Gosson or decomposed ore are all from the one crack going down the slope to the mine. Captain Flint tells Dick that gosson is Decomposed ore. No good in itself but a sign of good stuff lower down (PP28,35).