The dwarves have a long history with dragons. You may be able to learn something of the riddle of the dragon bones and Karazgar from the lore-masters of the Lonely Mountain.
'Why is it, then, that I cannot stop thinking of the riddle of the dragon-bones you told me of, in the Long Lake? And now you tell me this Karazgar appeared holding a dragon's tooth.
'Although dragons play no small part in the history of the Dale-lands, we know remarkably little about the beasts. The dwarves, however... they have long memories, and I know that dragons figure largely into their own histories. I think you should make your way to Erebor, ${PLAYER}, and learn what you can about dragon's bones and teeth, and what this man-of-rust might be after.'
Erebor is in the northern end of the Dale-lands.
You should travel to Erebor to speak with the dwarves there.
Víglund and the crowd stand before the gates of Erebor, in the northern end of the Dale-lands.
You should talk to Víglund about the dwarves gathered around the statue.
You should examine the axe embedded in the statue at the gates of Erebor.
You should examine the rust spot found at the gates of Erebor.
Víglund the guard can be found at the gates of Erebor.
You should tell Víglund your conclusion about the axe.
You should continue assisting the Dwarves of Erebor.
The Trail of Rust quest arc will continue after completing the Under The Mountain quest arc which begins with Órug in Erebor.
You should speak with Lore-masters Rúni, Spall, Fróthi, Mágsal, and Belgur in Erebor.
Górsim can be found in Erebor.
You should speak with Górsim about viewing the teeth of the dragon Scatha.