A most excellent find, Sir. I can't believe I'm at the top of the posts. I'm currently reading about the Panama Canal and it's origins, and the Darién Gap is mentioned prominently therein.
As you may know, Panama was once a Columbian Province until Teddy Roosevelt aided Panamanian rebels in their effort for independance. The payoff for the US was the Panama Canal. After the Panamanians declared independance, the US sent gunboats to Panama City and Colon, thereby making Columbian intervention via the sea an impossibility. The Columbian government then tried to send a large force of men into Panama through the the Darién Gap. The force, which consisted of Columbian military men acclimated to tropical conditions, was decimated by yellow fever in the Gap, and went back to Columbia en masse.
Walking TOWARDS the guerillas and speaking LOUDLY from almost a mile away?? I spent a couple years in the Canal Zone as a Medic in the 193rd Infantry Brigade in the mid 1970's. Just a bit north of the Darien Province. To avoid capure you just walk 25 yards or more into the jungle and lay low and be silent. You can't be seen or found. This National Geographic dude wanted a story, and didn't care about his companions or the danger to them. This area is not the wheatfields of Kansas. This asshole wanted to be found by the bad guys.
HAL9000, I have some good Canal history websites bookmarked if you would be interested..