The question of whether moose are native to Colorado has a complicated answer rooted in historical biology and modern wildlife management. While current thriving herds result from intentional reintroduction efforts, scattered evidence suggests a long, unstable presence in the region. Understanding the current status requires looking at the transient historical record, the specific actions taken by state wildlife officials, and the resulting population boom.
The Historical Status of Moose in Colorado
Historical records suggest that moose were only transient visitors to Colorado before the 20th century, typically wandering south from established populations in Wyoming. These animals, mostly young bulls, did not form a stable, reproducing herd within the state’s borders. Early settler accounts from the mid-1800s describe rare, individual sightings of these wayward animals.
Archaeological evidence offers a more complex view, with ancient moose remains dating back over 9,000 years found near Greeley. Moose bone tools were also discovered at Mesa Verde, indicating a presence across a long span of time. Wildlife biologists concluded that the species was largely absent for a prolonged period, leading to the classification of modern management efforts as a reintroduction.
Establishing Modern Moose Populations
The establishment of the current moose population began as a deliberate management strategy by the Colorado Division of Wildlife, now Colorado Parks and Wildlife (CPW). Starting in the late 1970s, the goal was to diversify wildlife viewing and create new hunting opportunities. The first major transplant occurred in 1978 when 24 Shiras moose—the subspecies native to the southern Rocky Mountains—were moved from Utah and Wyoming to North Park near Walden.
This initial group thrived, finding abundant food and lacking the native predators that historically kept populations in check. High reproductive rates, including a significant twinning rate, demonstrated the success of the transplant. CPW conducted subsequent transplants, moving moose to the Laramie River Valley in 1987 and the Upper Rio Grande River Valley in the early 1990s. These translocations led to a rapid population increase, exceeding 3,000 animals today.
Current Distribution and Habitat Requirements
Colorado currently has one of the fastest-growing moose populations in the lower 48 states, with herds spreading beyond their initial release sites. The Shiras moose, the smallest North American subspecies, is now prevalent in several mountainous regions. Primary concentrations are found in North Park and on the Grand Mesa, while other substantial herds inhabit the Laramie Mountains and the drainages of the Gore Range.
The presence of high-elevation riparian areas is a defining factor in moose distribution, as their diet relies heavily on willow browse. During summer, willow can account for more than 90% of a moose’s food intake, necessitating dense stands along streams and lakes. These animals, which consume 30 to 40 pounds of vegetation daily, also seek forested areas near water sources for cover and deep snow tolerance required for winter survival.
Safe Viewing and Coexistence
As the population expands and human recreation increases, encounters between people and moose are becoming more common, necessitating a focus on safety. Moose can weigh up to 1,000 pounds and run up to 35 miles per hour. They do not fear humans and will aggressively defend their space, especially a cow protecting a calf or a bull during the fall rutting season. Maintaining a significant distance is paramount, with wildlife officials recommending a minimum of 75 feet.
Recognizing warning signs is crucial for safe coexistence. Pinned-back ears, raised hair on the back, or a stomping front foot indicate a moose is agitated and preparing to charge. If an animal exhibits these behaviors or moves toward you, immediately run and quickly place a large, solid object like a tree, boulder, or vehicle between yourself and the moose. Conflicts are frequently triggered by dogs, which moose perceive as predators, so pets must be kept leashed and under control in moose country.