Wildlife viewing is bountiful in Rocky Mountain National Park—you might catch a glimpse of a soaring bald eagle or a marmot sunning itself on a rock. Larger animals are generally shy and do their best to remain unseen—it's a rare thrill to see a mountain lion or bear. Sometimes you'll simply hear some of the park's magnificent creatures rather than see them—hooting owls, howling coyotes and whatnot.
Smaller critters supply year-round entertainment. Squirrels abound, beavers build dams, barking pikas scurry across rock piles, and bats flutter about at dusk in Moraine Park. Big game animals are more likely to appear during fall and winter, but you may sight them in spring or summer, too. Spring lambing season is a prime time to observe bighorn sheep, but you'll also discover them feeding on natural mineral licks at Sheep Lakes in Horseshoe Park during summer.
Visitors spot elk (and the occasional moose) ambling along the Colorado River in the Kawuneeche Valley. Elk also congregate in Horseshoe and Moraine parks, and you'll probably see them grazing along Old Fall River and Trail Ridge roads as well. With some 3,000 elk roaming the park in the summer, you have an excellent chance of encountering these awesome animals. In fact, they frequently wander throughout Estes Park, especially in winter. If you're around during rutting season in September and October, you'll hear the otherworldly mating calls of bugling bulls.
Birders often visit during spring migration, although you can spy birds year-round. The park is a “Global Important Bird Area,” and with some 280 species, the potential for sightings is endless. You can sign up for a bird walk with a park naturalist, or bring your binoculars to observe from the trails or roadside pullouts. A choice birding site is the Endovalley picnic area, typically teeming with such diverse birdlife as the three-toed woodpecker; keep an eye on your food, as the feathered friends you make are on the hunt for tasty tidbits. The town of Estes Park also has a bird sanctuary along Lake Estes.
When viewing wildlife, be sure to keep your distance, secure pets inside your vehicle and be cautious of animals crossing the road (if there's one, assume others will appear). It's also important to refrain from feeding the animals—doing so may foster aggressiveness and decrease their chances of enduring the harsh winter.
For additional information about wildlife viewing in Rocky Mountain National Park and the surrounding area, check with personnel at the park visitor centers or at Estes Park Visitor Center, at the junction of SRs 34 and 36.