I'm certain this is possible. In my other guise I'm a Scout Leader- the kids managed to cook enough food to feed 30 odd people over an open fire, so I'm sure you could brew some beer. Just bring more wood than you expect to use- and an axe to split the logs smaller if you need more heat.
You won't get any smokiness in the beer, although I'm sure you'll smell great after. And don't use your best pot, because afterwards you'll have a choice of having a pot with a black bottom or having a pot with a scratched up bottom from having to take brillo pads to it!
It does sound like an awesome idea though. I like the idea of some nature managing to some how get into the beer...
You so lucky you have scouts to help you, man if I asked my teenagers and their friends they would be crackin up with no mobile signal. Mamas boys every one of them!
Beer is an expression of the human spirit. . . we use technical sciences as a tool to create it but its essence is and always will be a form of art - Handbook of brewing, chapter 2, page 55