The controversial effort to bring gray wolves back has had mixed success. Of the first 10 wolves brought in from Oregon, dubbed the Copper Creek pack, just six remain in the wild, with one having been recaptured and three killed, Coloradoan.com reported.

Colorado Parks and Wildlife officials began working to capture gray wolves in Canada on Friday as part of the state's wolf reintroduction plan.

Wildlife officers have begun the operation to capture gray wolves in British Columbia, Canada, and bring the apex predators to Colorado, where they will be released in a region at