When I went to Rocky Mountain National Park I learned about the four distinct life zones that exist in Colorado.
First is the Eastern Plains Zone (up to 6,000 feet) which is comprised of wildflowers and grassland and is home to many small animals like prairie dogs and rabbits.

Next is the Foothills Zone (6,000 to 8,000 feet) is composed of small bushes and trees such as scrub oak, juniper, sagebrush and pinion pine and is inhabited by raccoons, skunks, various squirrels, deer and an occasional bear and mountain lion.

The Montane Zone (8,000 to 10,000 feet) has various wildflowers and small shrubs, but large forests of pines and Douglas fir, as well as the colorful aspen tree, are predominant. Deer, elk, bear and mountain lions can all be found at this attitude.

The Sub Alpine Zone (10,000 to 11,500 feet) is less hospitable. Englemann spruce, Douglas fir and bristlecone pine comprise the area’s dense forests. It is estimated that some bristlecone pine trees on Pikes Peak are over 2000 years old.

In the Alpine Zone (11,500 feet and above), tundra composed of tiny flowers, mosses and lichen eke out a cold existence in the short growing season.