Eric, have you seen the full-length feature. Really wonderful, stunning in fact. I understood from a friend who knows the Benson brothers well that this film was made because a previous film-making effort between John Howard Benson & . . . (I'm sorry, but I'm forgetting the name, will check into it and repost) because that effort never materialized as the filmmaker & Benson kept editing the footage down until it was just a pile of clip on the floor. I've heard some footage still exists though, in the archives at MOMA? (Again, I'll seek clarification from my friend & repost) . . . some fragments of JHB walking through a field of reeds.
The footage exists in MOMA, the documentary's collaborator was Robert Flaherty, and the reed was Phragmites communis.
Just as a matter of factual confirmation, in the very last video of the Printed Picture website ( http://www.benson.readandnote.com/ ) in the last 90 seconds, Richard Benson is telling a story about Paul Strand using Robert Flaherty darkroom. Someone says "Flaherty made Nanook of the North, and Benson says, "and he made a movie of my father too."