Colorado National Monument's varied terrain attracts many animals to live, nest, or hunt within its boundaries. Among mammals, the mule deer are the largest commonly sighted by visitors. However, coyotes, mountain lions, bobcats, and desert bighorn sheep are also occasionally seen by a lucky visitor. Smaller mammals like foxes, desert cottontails, squirrels, and other rodents are often seen scampering off the sides of the Rim Rock Drive or hiking trails.

The towering walls of the various canyons in the monument are a perfect place for raptors and songbirds to raise their young. Golden eagles, red-tailed hawks, and turkey vultures often soar aloft on the air currents; Gambel's quail scurry across the trails; and the calls of the mourning dove and the canyon wren echo in the canyons. The various overlooks are excellent places to watch the acrobatics of the white-throated swift just below the rim. Bright blue scrub jays are a common and colorful sight throughout the monument.

Reptiles are generally seen in the monument from early March to late October. They are most visible in May and June, and are active on warm, sunny days and mild evenings. Watch for yellow-headed collared lizards or the plateau whiptail, especially during late morning or late afternoon hours; they are often seen sunning themselves on the warm rocks. Snakes do exist in the monument, but only one, the midget-faded rattlesnake, is poisonous and is rarely seen.

Following summer thunderstorms, listen for calls of frogs or toads in the canyons. Amazingly, there are several species of amphibians that thrive despite the monument’s semiarid environment. Their ability to burrow underground and remain dormant for brief or extended periods of time gives them a high tolerance to temperature extremes and drought. Following heavy rains, several species, like the red-spotted toad or the canyon tree frog, surface to take advantage of seasonal water sources. As most species are primarily nocturnal and well camouflaged, they are rarely seen, but if you listen, you may hear them calling late in the evening.