When you are leaving your property to go onto someone else’s property to shoot them, however, my guess is that Colorado law looks differently on that...
Yep, I agree with that. The guy is probably going to jail for shooting the animals on land other than his, especially the BLM land. Still, this open range requirement that you are responsible for other folks animals staying off your land instead of the owner themselves is a remnant of the notion that the range belongs to everyone (and by extension, no one) and is a socialist view of property rights.