Follow tylers link above about the coconut oil. That is a great source of calories when on the trail...as long as it is not hot. The stuff melts! (just need a tight container in this case) I am no where near the outdoorsman you are but when I go out and need to really conserve weight I make some jerky (www.paleodiet.com
look for the food prep links or something like that) dried fruit and coconut oil. I pack a multivite and that is it if I am really bare-bones-ing it.
The adaptation to fat happens over several weeks. Eating more fat is the main driver for the shift...the body tends to burn whatever macronutrient is in excess...that is why being a sugar burner sux!
A voracious appetite without bloodsugar crashes sounds pretty good to me. The difference between being hungry and "hormanal hunger" from an insulin crash I am sure you are noticing to be quite pronounced. Much less snappyness and roadrage!
Im glad things are going well!