In mountainous terrain, particularly with a decent map, you can easily maintain orientation by observing the features around you.
Good point. I've always heard that given the choice between a map and a compass, take the map. "Terrain association" is a great technique. I've done week long hikes involving cross country travel in the Sierra where I referred often to my map but seldom to my compass. Even when I am using a compass to calculate my position, I always try to do a "reasonableness check" based on terrain association. I don't care how good you're calculations are. If the terrain doesn't match up, it's not the terrain that's wrong!
HJ