That picture you posted is from the Roger Patterson/Bob Gimlin video. I saw where researchers tried to expose the footage as a hoax. A couple of other characters surrounding the famous video came forward--one who claims to have worn the suit, Bob Heironimus, and Philip Morris, who says he sold it to Patterson and Gimlin.
That side here.
Now check out what the Bigfoot Field Research Organization has to say about it here.
Numerous documentaries experts have studied the gait and found it to be odd at the very least. Also, the length of the arms and distance between steps is still puzzling.
Judge for yourself. The clip:
A good book to check out, The Bigfoot Film Controversy, can be purchased here.
Also, the tribe photo you posted was recently exposed as a hoax, then clarified as not a hoax, just misrepresented:
"The story is not a hoax, and none of those involved in working to protect these Indians' rights have ever claimed they were 'undiscovered.'"