I have seen it happen many times. Several years ago I was in the mountains bear hunting and stopped by an outfitters camp to visit and see if they had seen any bears. They had just loaded the pack string (mules) and was getting ready to head into the back country. As I was talking to the one outfitter his partner was climbing onto his horse, as his butt hit the saddle the horse exploded. He dropped the leadrope for the packstring and was hanging on for dear life. But after about the 6th jump he parted ways with the horse in a nice big ark through the sky landing on his hip on the graveled parking lot. Now this gentleman looked to be about 60 so I was figuring that I was going to be calling lifebird but he layed there and finally got up limping but unhurt. The funny thing was the packstring never moved, they just stood there and watched the whole thing.
Our packstring of horses were a couple miles out from the trailhead when we observed a packstring of four mules loaded with elk and mule deer led by a wrangler on a horse coming our way. Two mule deer bucks broke out of the timber into the meadow just behind the mules. Rear mule spooked and took the other three with him right at us and they passed us bucking and braying. Panniers and horns started flying everywhere.
Our horses went wide-eyed and fidgeted a bit but stayed in formation. Thought sure we were in for a wreck.
