Some more advice I thought of today:
Some of the gun hunters I was with remarked that the caribou seemed pretty stupid sometimes. For example, one of the caribou would be shot, and the others would run for a bit and stop and look back. I replied that making the connection between the gunshot and a dead animal and then back to the guys hunting is quite an intuitive leap for animal that may never have seen humans before! Bowhunting means you're a lot closer and they're more likely to associate you with danger.
Don't make the mistake of thinking the animals are stupid! They're certainly not as high strung as whitetails, but their survival strategy (herd animal) is different than others. The calfs seem pretty dim, but that's true of many young animals.
We didn't get into the main migration either. If we had, we may have seen some bigger bulls. Apparently the difference between the big bulls and the little guys is similar to the difference between mature whitetail bucks and immatures - to the point of following different trails and staying off the exposed ridges.