Hmmmm, well as far as elk go: If you're hunting public land, no outfitter, no guides, no scouted game... elk are hard to tag. 'Course, if you want to spend the cash you can snag a P&Y bull pretty easily. I've hunted mountain goat with a bow and they would have to have my vote. I've never hunted bighorns (like everyone says, tags are scarce) but in the area I lived in, if you had a tag, you'd snag a ram. But, if they were hunted harder, I'd feel they would rank right up there with goats. But by far I'd have to say that the mountain goat in terms of terrain is the toughest. On top of that, they tend to spot you LONG before you spot them. They are, after all, related to the pronghorn and have similar eyesight. They'll spot you coming over a mountain and they can scamper up cliffs that'd make you puke! Then, if you're lucky enough to hit one and he dies quickly without falling down a mountainside, you still have to pack him out. It's almost nice when you shoot them and they roll... it's easier to pack 'em out! But then, you end up with broken horns most of the time. So, in short, my vote goes to: The Mountain Goat!