What is Buck’s legacy in Call of the Wild?

From the text:

But more remarkable than this the Yeehats tell of a Ghost Dog that runs at the head of the pack. They are afraid of this Ghost Dog, for it has cunning greater than they, stealing from their camps in the fierce winters, robbing their traps, slaying their dogs, and defying their bravest hunters.

Nay, the tale grows worse. Hunters there are who fail to return to the camp, and hunters there have been whom their tribesmen found with throats slashed cruelly open and with wolf prints about them in the snow greater than the prints of any wolf. Each fall, when the Yeehats follow the movement of the moose, there is a certain valley which they never enter. And women there are who become sad when the word goes over the fire of how the Evil Spirit came to select that valley for an abiding-place.

Buck ultimate legacy is the story of the Ghost Dog, and the pack (pups) he leaves behind.