Open range laws vary from state-to-state. Apparently on the “open range” if you don’t want someone else’s livestock on your property, you have to fence them out.
Hit a cow, you must reimburse the rancher. Who *owns* this land, anyway? Things are murky, to be sure.
Barbed wire is what tamed the Wild West. The gov't fences the general public out of all sorts of places (try strolling in on the NSA in MD)