I’m posting the same question on the Comics Journal message board. Maybe a passer-by here will also have some info.
Anyway … Krazy Kat sure reads like it was marijuana inspired. Of course it’s tedious to assume that pot lies behind anything strange and original; I wouldn’t say Dr. Seuss or Thurber were stoned. But Krazy Kat has that air, don’t ask me why.
Googling turned up nothing but this mention by, I think, Skip Williamson (scroll down a good ways or do a word search). And the Library of Congress lists a book on Herriman that I may track down someday.
Resources aside, what’s the comics-world conventional wisdom on the question of Herriman as pothead?