Both male and females soon grow horns after birth. Older Big Horn Sheep's horn sometimes have horns over three feet long. Adult Big Horn Sheep's horns sometimes weigh over 30 pounds. Ewe's horns are shorter and usually don't bend.
When Big Horn Sheep fight, which determines the dominant animal, they ram each other with their horns and that also determines who gains possession of the ewes.
Big Horn Sheep breed during breeding season, typically July through October. The process takes about 150-180 days then, the lambs are born usually in late winter.