Rams are typically 5 to 6 feet tall (1.5 to 1.8 meters) from head to tail, and weigh 262 to 280 lbs. (119 to 127 kilograms), though they can grow to over 300 lbs. (136 kg). Rocky Mountain bighorn rams have massive horns that weigh more than all of the bones in their bodies. A set of horns can weigh 30 lbs. (14 kg). Ewes, or female bighorn sheep, typically weigh 30 to 40 percent less than the rams, according to the National Bighorn Sheep Center.