I've blown up the pic a little bit so you can see it properly:
http://i617.photobucket.com/albums/t...ear/oldpic.jpg
With sensible cap on, it looks like people around some kind of totem - and totemic rituals were part of prehistoric American culture, evolving into what we know as Red Indian totem poles.
However, with my Doctor Who hat on, I start to think - if time travellers wanted to visit the past, they'd have to go somewhere where they were least likely to be recorded as having visited, so why not an era where they can't be photographed, and it's unlikely that written evidence will survive, thus leaving us with ambiguous cave drawings? It makes you wonder.
By the way - I have to do my mandatory thing that I do in time travel threads. If anyone's reading this during an era when time travel is possible, maybe in an archive, please don't be shy, come and visit and tell me about the future! I won't tell anyone - no-one'd believe me anyway

See you soon!