Moose are present in the Rocky Mountains, which provide the diverse ecosystems necessary to support one of North America’s largest land mammals. This environment is particularly suited to a specific subspecies, allowing populations to thrive across several states and provinces.
Confirming the Presence: The Shiras Moose
The specific subspecies of moose in the Rocky Mountains is the Shiras moose (Alces alces shirasi). This variety is the smallest of the four North American subspecies, yet it remains a formidable animal. Adult Shiras moose typically stand between five and six and a half feet tall at the shoulder and weigh 600 to 1,200 pounds, making them the largest member of the deer family in the region.
They exhibit a slightly lighter, more rusty yellowish-brown body color compared to the darker coats of the larger Alaskan or Eastern moose. Their antlers are also noticeably smaller and less expansive than those found on their northern cousins, which is an adaptation to the mountainous terrain they occupy.
Specific Geographic Range within the Rockies
The distribution of the Shiras moose extends throughout the Rocky Mountain chain, forming a distinct population separated from other North American moose. Their core range is concentrated in the high-elevation areas of the western United States and southern Canada.
Robust populations are found across Wyoming, Idaho, Montana, and Colorado, with a presence in northeastern Utah and northeastern Washington. Wyoming is considered the core of the Shiras range, including the Bighorn and Wind River mountain ranges. Further north, the range extends into the Canadian provinces of southern Alberta and southeastern British Columbia.
Moose are not uniformly distributed but are concentrated in specific pockets that offer suitable water and forage. In Colorado, for example, the modern herd began with introductions in the late 1970s and now occupies many higher-elevation habitats, often tied to protected areas like national parks and forests.
Essential Habitat Requirements
The presence of moose in the Rockies is directly linked to the availability of specific environmental conditions, particularly access to water and preferred vegetation. Moose are highly reliant on riparian areas, such as wooded stream bottoms and marshy habitats, which are rich in the woody vegetation that makes up the bulk of their diet.
Willow is a primary forage source, constituting a large percentage of their diet year-round. They also browse on other woody plants like aspen, poplar, and birch, and wade into lakes and streams to consume aquatic vegetation. Summer range selection is influenced by features that provide high-quality forage and limit thermal stress.
Moose typically migrate seasonally, moving to higher elevations during the summer months to forage on lush vegetation and escape biting insects. As winter approaches, they often shift to lower elevations to avoid deep snow. They may also move into mature conifer forests, such as those with Engelmann Spruce and Douglas Fir, which provide abundant cover and some forage when riparian habitats are limited.
Viewing and Safety Guidelines
Encountering a moose in the Rocky Mountains requires maintaining a safe distance to ensure the well-being of both the animal and the person. Experts advise keeping a distance of at least 50 yards from any moose. Moose are generally not aggressive but will defend themselves and their young if they feel threatened.
Signs of agitation include flattened ears, raised hair on the back of the neck, or a lowered head. If a moose displays these behaviors, back away slowly and calmly, trying to put a large object, such as a tree or car, between yourself and the animal.
The best times for viewing moose are during the early morning and late afternoon hours when they are most active. Moose are commonly spotted near water sources, such as in the meadows of river valleys or near beaver ponds. Moose can be particularly aggressive during the calving season in late spring and the rutting season in the fall.