IANAL, but what you linked directly contradicts what you stated about ranchers paying for the damage (assuming the case of signed grazing areas). And with that, I'm done with the armchair lawyerin'. May neither of us discover the truth of liability the hard way.
Signed grazing area is not a contradiction, its very specific. I have discovered the liability as I had to help with the bison case. So I guess I was fortunate it wasn't my car.