I would like to share with you my finding when I was preparing my movie 'On the Set Of First Blood'
I'm pretty sure no Rambo fans has noticed the interesting and strange 29'20 frame.
During the filming of First Blood in Othello/Quintette tunnels area (Nov-Dec 1981), there were NO footbridge across the river. It was NOT opened for tourists. The tunnels were there, left over from a rail line. But any bridge it might have utilized was long time gone.
The Rambo Tree spot was closed to the river and the only convenient way (for the movie crew) to access it was this short tunnel shown on this rare photo http://sly1982.sl.ohost.de/gallery/fb178.jpg
As you may know, during the post-production, the movie went back and worth to the editing room. I do believe the conversation in this room between the director Ted Kotcheff and his editing guy -Joan E. Chapman could have been something like this:
[Ted Kotcheff] - Even if the sequence lasts 1sec, I want the audience to focus on Rambo throwing the rock. This tunnel entrance might distract their attention. Is there a way we can remove or hide it?
[Joan E. Chapman]- Yes. I just need to superpose a frame on it. Nobody will notice.
Yes. Nobody has noticed until now.
Ok. This is not a national treasure discovery. I think it is worth to mention it ;)
If you are interested to know more about Othello Tunnels, this is an interesting link