Next time you're watching the opening credits, pay close attention for this one. As the choppers land on the pad, Hawkeye, wearing his blue Hawaiian shirt, is in a huddle with some others. Look above them to the mountains of southern California, and you'll see telephone poles.

Actually in the ep where Cowboy has Blake in the chopper and gonna kill him in the background on a hill there was a very very blatent and easily spotted radio tower (I would say cell phone but I don't remember how far back they existed.) This was so easy to see that my wife saw it about the same time I did, and usually I need to pause a movie and point it out to her. She's definately not a nitpicker like me, (or as she says not as repressed.)