_A hunting group now has the chance to make its case for using sharpshooters to thin the elk herds in Rocky Mountain National Park. The 10th U.S. Circuit Court of Appeals ruled Wednesday that a lower court erred in not allowing the Safari Club to become a party in a lawsuit filed by an environmental group. WildEarth Guardians filed its lawsuit in 2008 after park officials approved a plan to use federal and state employees as well as volunteers to kill elk in the park. WildEarth Guardians said park officials didn't fully consider the release of wolves to reduce the herds before it decided on sharpshooters. Park officials say overgrazing by the elk herd in and around the park has damaged habitat and threatened other species.