Vintage Real Photo Postcard. Depicting Bighorn (Mountain) Sheep in Canada. Photo by Byron Harmon, Banff, Canada. Divided back, Condition: This is an original photo postcard, not a copy or reproduction. It is in very good condition. Comments: The bighorn sheep is a species of sheep native to North America. It is named for its large horns. A pair of horns might weigh up to 14 kg; the sheep typically weigh up to 143 kg.