I think it's related to the ring and the Lodge. We knew it was related to the american native people, as Hawk told Cooper about the dweller on the threshold and his "people". From The Secret History of Twin Peaks:
Letter written by Meriwether Lewis to President Thomas Jefferson. Dated september 25, 1805:
«Twisted Hair [Native American Indian Chief] became agitated when I [Meriwether Lewis] pressed him for more information on this matter [Owl Cave ring]. He pointed to the symbol on the ring, turned it upside down and said something that our Shoshane guide couldn't fully translate about an owl, which one could say the symbol, viewed from that angle, vaguely resembles. [...] Our guide soon afterward told me in confidence that the chief had said the ring was related in some way to the "spirit world" is part of their pagan belief system and, from all I've gleaned to date, bears no relation to our Christian God; for instance, as I understand it, they might see an animal like an owl as in some way divine. [...] The chief has given me the ring mentioned above to take along, but with emphatic gesture indicated IT SHOULD BE LEFT IN ITS POUCH AND UNDER NO CIRCUMSTANCES WORN.»
This is very interesting, a passage where Meriwether Lewis tell about the Lodge, and how the natives know about it.
Excerpt from a journal found in the private papers of President Thomas Jefferson. Undated: Late 1805 (?):
«It begins [Lewis's dispatches] with a more or less direct account of traveling three days due north from the main body of the Corps to a "certain location" that Lewis says was revealed to him on a recently drawn native map. At which point I am then treated to a disjointed assortment of passages that defy categorisation, i.e.:
"Lights from the sky, the silvery spheres... music, like some heavenly choir... fire that burns but does not consume... colors unseen or unimagined, flowing from all things... gold, all gold bright and shining..."
[...] Nearly a page of lunatic ranting about "the secret deep within the color red." Puzzling references to classical statuary, black lines-and a thoroughly incoherent discourse on the "mysterious force B. Franklin had stumbled upon."
Finally, the fragmented and feverish mention of an uncanny encounter with a "silent man." His last words in this vein [...]: "I SHOULD HAVE HEEDED HIS WARNING."