Are There Pelicans in Colorado?

Colorado's breeding pelicans favor high-altitude lakes and reservoirs in the state's mountains and western plateaus. Blue Mesa Reservoir in the Uncompahgre National Forest, Antero Reservoir in the central Rockies, and various water bodies in northwest Colorado host the largest colonies. These large, shallow lakes with protected shorelines and adequate fish populations provide ideal nesting habitat. The birds establish colonies on islands or remote peninsulas where they can raise chicks sheltered from ground predators. Not all reservoirs attract pelicans every year, and colonies can shift based on water levels and fish availability. Spring visitors to Colorado's mountain lakes often spot them on the water's surface, especially during April and May when breeding activity is intense.

April through June is the prime season for pelican watching in Colorado. Activity peaks in May, when most breeding birds have arrived and established colonies. April marks the influx of spring migrants moving north, while June sees continued breeding activity though some early fall movement begins. July and August witness declining numbers as chicks fledge and birds prepare for departure. By September, observations drop significantly, and by November, most pelicans have left the state. Late March and early April can be rewarding for catching the first arrivals, but May remains the single most reliable month for encountering American White Pelicans in Colorado.

American White Pelicans are the only pelican species that regularly occur in Colorado as a wild population. Brown Pelicans, which breed along the Pacific and Gulf coasts, are vagrants to Colorado and are not considered residents or regular migrants. If you see a pelican in Colorado, it is almost certainly an American White Pelican. These large, white birds with black wing markings are unmistakable, especially when gathered in flocks on reservoirs. Rare sightings of Brown Pelicans outside their normal range have been recorded, but they do not breed in Colorado and are not expected in the state's wildlife communities.

Many Colorado reservoirs that host pelican colonies allow fishing for rainbow trout, kokanee salmon, and walleye. However, access to specific breeding colonies and nesting islands is typically restricted during spring and early summer to protect eggs and chicks. Check with Colorado Parks and Wildlife and the managing agency for each reservoir for current fishing seasons and any closures related to wildlife protection. Some breeding areas lie within national forests or are managed as protected sites where human activity is limited during nesting season. Fishing is generally compatible with pelicans outside the critical breeding window, and summer and fall can offer good angling opportunities after most nesting activity concludes.

American White Pelicans are protected under the Migratory Bird Treaty Act, which prohibits killing, capturing, or harming the birds or their eggs without federal permits. Colorado Parks and Wildlife enforces state wildlife laws that provide additional protection. These protections ensure that breeding colonies remain undisturbed and that populations can raise young successfully each season. The federal protection recognizes pelicans as migratory species essential to North American ecosystems. If you observe pelicans, you can watch and photograph them from a respectful distance, but approaching nesting colonies, touching eggs, or disturbing birds is illegal and harmful.

American White Pelicans are fish specialists. In Colorado, they primarily target fish in the 2 to 10-inch range, including kokanee salmon, cutthroat trout, whitefish, and carp. They hunt cooperatively, swimming in lines or V-formations to herd schools of fish into shallow water, then diving or dipping their bills to scoop up prey. Unlike diving pelicans of ocean coasts, American White Pelicans feed by surface feeding and shallow dives, often in groups. A single pelican can eat several pounds of fish per day. Their large bill, with its distinctive pouch, holds water and fish during feeding. Colorado's cold, high-altitude lakes provide excellent fish populations that support breeding colonies and fuel migration movements.

Pelicans are migratory birds that follow the availability of open water and abundant fish. In winter, high-altitude Colorado lakes and reservoirs freeze, making feeding impossible. As snow melts in spring, water levels rise and fish become active, attracting pelicans northward from wintering grounds along the Pacific coast and southwestern U.S. reservoirs. Breeding takes place during the brief window when weather permits and fish populations are robust enough to sustain thousands of birds and their young. By late summer, breeding concludes and pelicans depart for regions where open water and food remain abundant through winter. This migration pattern has sustained American White Pelicans for millennia and continues today across the western United States.

American White Pelican populations are stable and recovering from historical declines, but they face ongoing challenges. Habitat loss and water management practices that reduce open-water habitat threaten breeding and wintering sites. Pesticides and lead ammunition can accumulate in their tissues through consumed fish. Climate change alters snowmelt timing and reservoir water levels, potentially affecting the synchrony between pelican arrival and peak fish availability. Human disturbance at nesting colonies during spring can cause breeding failure. In Colorado, responsible management of reservoirs and protection of key breeding sites by Colorado Parks and Wildlife and federal agencies supports pelican populations. Observing pelicans from a distance and supporting wetland conservation helps protect these remarkable birds.

American White Pelicans breed throughout inland western North America from British Columbia to Utah and across the Great Plains. Major breeding colonies occur on large lakes and reservoirs in Montana, Wyoming, Utah, Idaho, and the Great Lakes region. Winter populations concentrate in California, coastal Mexico, and southwestern reservoirs. Migration routes connect breeding and wintering grounds, and pelicans may stop at lakes and reservoirs across the entire region. If you plan to see pelicans elsewhere, similar high-altitude lakes in Wyoming and Utah offer excellent opportunities in spring, while coastal California provides winter viewing. The species is widely distributed and relatively easy to find in suitable habitat throughout its range.

Colorado's lakes and reservoirs host a diverse waterbird community. Great Blue Herons, the most frequently observed waterbird in Colorado, often share habitat with pelicans and can be seen standing or hunting on shorelines. Snowy Egrets, Cattle-Egrets, and Great Egrets also occur in Colorado, though less commonly than herons. Cormorants, grebes, ducks, and geese round out the waterbird community depending on season and location. Many of these species overlap with pelicans during spring and early summer. For a complete guide to Colorado's water birds and where to find them, visit /wildlife/colorado. Spring visits to major reservoirs often reward birders with multiple heron, egret, and waterfowl species in addition to pelicans.