Yellow - Bellied Marmot (whistle pig): Close relative of the woodchuck of the East and Midwest and the largest of the ground squirrel family. Brown in color with white areas on the chin and a yellowish belly (hence the name). Adults weigh up to 11 pounds and are about 26 inches in length. During hibernation the marmot will loose half of its summer weight. Insufficient fat or a burrow too shallow to prevent freezing will cause marmots to not arouse in the spring. Mating season starts as soon as there is green forage available. Gestation takes 30 days; approximately three to eight offspring are born and weaned in 20 to 30 days. Preferred foods are flowering stalks and assorted grasses. Marmots live in colonies with a single male and several females. Predators are less of a problem than the stress of hibernation. Marmots are protected by their rocky habitat and the social system of alarm calls.

Bighorn Sheep: The Bighorn Sheep is the state animal. Colorado is home to the largest population of the species anywhere. The animals are 5 to 6 feet long with a tail 3 to 6 inches in length. Rams weigh 150 to 250 pounds, ewes weigh 123 to 200 pounds. Males are 3 feet high at the shoulders, ewes slightly less. Grayish brown in color with a white rump patch. The massive, coiled horns make up 10% of the body weight. Ewes have spike-like horns. Bighorns are grazers and eat over 100 different types of plants, feeding in meadows, open woodland and alpine tundra. They often retreat to rest on inaccessible cliffs. Pikes Peak has a herd of about 250 to 300 head that stay near timberline year round. The rut (mating season) takes place in the late fall, with the rams butting their massive horns to assert their dominance in order to get their chance of breeding. Females breed after they are 3 years old; gestation period is 6 months; a single lamb is born in May or June.

Black Bear: Colorado's largest carnivores: 4 - 6 feet long and weighing 200 - 450 pounds. They are black (or occasionally brown) in color. Black Bears are omnivores, eating about anything in good supply- fruit, nuts, honey (bees, waxy comb and all), young deer and elk, birds, eggs, insects. Their only enemy is humans. Mating occurs in the summer; 2 or 3 cubs (9 ounces) about the size of two or three fists are born to a sleeping mother during hibernation. The cubs will emerge from the den five weeks later after their weight has doubled four to five times, to 6-9 pounds, and the young play among themselves. The cubs don't reach full size until about five years of age. Females breed every other year. Longevity in the wild may exceed 20 years.