U.S. #1078 was the second of three stamps commemorating Wildlife Conservation in America. It was released at the annual convention of the Colorado division of the Izaak Walton League, an environmental organization founded in 1922. The league promotes the protection of natural resources, as well as outdoor recreation. Pronghorn Antelope – Conservation Victory The Pronghorn Antelope first became known to Americans during the Lewis and Clark Expedition. Its name can lead to confusion, as it is neither an antelope or a deer. Its scientific name, Antilocapra Americana, means “American antelope goat” – but it’s not a goat, either. Instead, it belongs to its own scientific classification. Before the arrival of European settlers, the pronghorn population was an estimated 25 million. By 1920, that number had fallen to about 17,000. Conservation efforts have helped the pronghorn antelope increase to approximately half a million today.