Nanook of the North is a great source of information about a controversial period of time in the history of the North America. Whether we look at the movie as an inaccurate or a perfect reflection of the involved tribes in it, I believe that it still contains the characteristics of a fully-fledged documentary. I mean it is unfair to compare a documentary done at CNN or BBC with this one and the reason is clear for everybody. I look at this documenrtyy, with all the criticism it received,  as a good account of the story of some tribes residing in the North. Here is a good source of information about the movie and its maker:
http://www.oneworldmagazine.org/seek/nanook/main.htm

Hussain