Daily Postcard: A bull elk spotted recently at the Valles Caldera National Preserve. Adult male elk, referred to as bulls, attain their largest size at 7 years old, averaging 5 feet tall at the shoulders and weighing 700 to 1,100 pounds. Bull elk are the second largest members of the deer family (moose are the largest). Antler growth is in preparation for the elk mating season, which primarily occurs in September and October. Antlers can weigh up to 40 pounds per set. Velvet, which covers antlers during the growth phase, carries blood to the growing bone tissue. During the summer months, antlers can grow up to one inch per day, making it the fastest growing bone known. Source: www.fs.usda.gov. Courtesy/New Mexico Tourism Department