The life zones of Colorado's Front Range are determined by elevation, which correlates with annual precipitation. The major cities of the Front Range stretch along the Colorado Piedmont, which averages 15 inches of precipitation per year, most of which falls as snow. Receiving just a few inches more, a zone of Shrublands covers the lower slopes of the foothills, ranging in elevation from 6000 to 7500 feet (higher on south-facing hillsides). Adorned with colorful rock formations, this ecosystem harbors a unique mix of vegetation and wildlife.
Yucca-studded grasslands are broken by stands of Gambel's oak, mountain mahogany, wax current, skunkbrush and other drought tolerant shrubs. Willows and cottonwoods line the drainages and pockets of juniper cloak the hillsides; in southern Colorado, pinyon pines are also found in this zone. Scrub jays, black-headed grosbeaks, lesser goldfinches, yellow-breasted chats, white-throated swifts, cliff swallows, Say's phoebes, rufous-sided and green-tailed towhees, rock and canyon wrens, Virginia's warblers, lazuli buntings and common bushtits characterize the bird population; golden eagles are also common here, soaring above the canyons by late morning.
Shrubland mammals include rock squirrels, Colorado chipmunks, raccoons, red fox, coyotes and mule deer; ringtails inhabit this zone in southern Colorado. Mountain lions haunt the shrublands but are primarily nocturnal and rarely seen; a more common danger are western diamondback rattlesnakes, which are best avoided by staying on designated trails. Red Rocks Park, west of Denver, Roxborough State Park, southwest of Denver, and Garden of the Gods, in Colorado Springs, are all excellent places to explore this life zone.
