Rocky Mountain goat

noun
1.
a long-haired, white, antelopelike wild goat, Oreamnos americanus, of mountainous regions of western North America, having short, black horns.
Origin
1835-45, Americanism
British Dictionary definitions for Rocky Mountain goat

Rocky Mountain goat

noun
1.
a sure-footed goat antelope, Oreamnos americanus, inhabiting the Rocky Mountains. It has thick white hair and black backward-curving horns