They actually didn't. Wolves comprise several species and sub-species. What was put into Yellowstone was the non-native Canadian Grey Wolf.
If I was in Colorado I'd sue to force them to stock the actual native species of wolf in that state ( probably the Plains Wolf) and not the non- native invasive species they probably want to use.
Stocking any wolf back is idiot thought. Ranchers and deer and elk, mountain lions and coyotes think they all suck. I live in the Rocky Mountains the government stopped hunting them. I didn’t.