I would have to say no on this one. If they are owned by someone,private or otherwise, and they get out off of their property this doesn't mean they are no longer the owners animals. However, Maybe I am missing something here because I am not sure of your situation in Sask.
We have had folks(poachers) shoot animals from our herd right in our fields and claim they thought they were wild(this has happened numerous times and mostly on crown leases we own). Sad sad sad.
Are there any wild herds of Buffalo even left in Canada that you could hunt?
I should also add that free range Buffalo is not very tasty compared to a properly finished animal. I would never pick a grass finished animal over a grain finished animal. Just me, but free range is gross.