Eric Valli spent 3 years taking photos of people in the United States who have "decided to live light on the earth." The photographs are terrific. It looks like Valli spent time with two clans: a frontier/settler type group, and another group that look almost like cave people. I wish he had included more information about them!
UPDATE 10-17-2013: Quite a few TV production people have contacted me over the months wanting to know how to get in touch with the people in Mr. Valli's photos. If you are a TV production person, please read the paragraph above. Don't email me about this. I don't know anything about the people in the photo!