I must admit I feel horribly smug when I see signs in movies that the filmmakers obviously don't know some of the outdoorsy stuff I, by now, have learnt thouroughly. For example, unless you live in the tropics, you will always sleep in a fetal position outdoors. And in this movie, Redford rushes into the cabin of another mountain man, "Bearclaws" one cold day, and starts cutting himself some meat without closing the door. This is simply inconcievable, if you're cold all day you're hardwired to preserve heat at all costs.
Still, it's a pretty good movie, moving at a 70's style slow clip that leaves quite a lot to the viewer's imagination, and without much of an attempt at "realism". In fact, Jeremiah Johnson channels my daydreams almost perfectly. Ah, to sit in a tipi, clad in leather and chewing the fat in some obscure native american language!