Regarding history of Baekdu Mountains...

Nov 2009
1
Was it ever been within the territory of the Manchurian Qing empire prior to the Gando treaty?

Yes, I do know that the current border has been negotiated between PRC and North Korea and finalised in 1962, but I'm still curious as in if this area have ever been excluded from ancient korean kingdoms prior to the Gando treaty in 1909.