Not even Obata's granddaughter knows the answer to this. Maybe it is unanswerable, that is, it will remain a mystery or Obata fibbed or took some artistic license..
Obata did at least two paintings mentioning Death's Grave Pass which appears to be somewhere northeast of Pywiack Dome, northwest of DAFF Dome . It is on no map. I have used Obata's descriptions of paintings to locate other sites where he obviously painted from. Those were accurate accounts. I have spoken to many rangers. Some ideas but none were right except maybe "Obata made the name up". Any ideas or better yet, facts?
Ralph