Ya pretty much have to be on private property. The Blacktailed P-dog has erroneously been listed as endangered in CO, thanks to a few counting "errors", and no shooting can take place on public ground.
Knock on some doors. I heard the DOW might even be able to give you some names and numbers of ranchers that still want them removed....not sure on that one, a friend mentioned it the other day.
Better yet, head up to Wyoming and knock on some doors. They want 'em all gone.
I'm itching to pop a few myself. My Savage 112 in .223 has been silent for way too long.