Bear Hunter,
I think the best policy would be to unload the weapon before crossing a fence, a stream, a ditch, or any other such obstacle afield. Being totally honest, however, I cant say I always take the time to do so. But I will stress that I make SURE that my weapon is never chambered and ready to fire. That begs disaster. I do think it is reasonably safe, however, if you have shells or cartridges in the magazine. And that applies to back-up weapons like a handgun as well. Crossing a fence - whether under or over -- I would sit the weapon down, cross the fence, then reach back and get the weapon (or vice versa). I would not attempt to cross with it in hand or strapped on. This may not be practical crossing a stream or a ditch. In those cases, I would keep it in hand so that if I started falling, I could release the weapon if I had to. I know this sounds terrible, but better to loose a gun than to risk having it go off on you by falling on it. Never take safety for granted in these enocunters. This is the exact kind of thing that causes an accident. Those are my thoughts. Woodsman.