Idaho has a significant population of moose, offering viewing opportunities across the state. The subspecies found in the Rocky Mountain region is the Shiras moose (Alces alces shirasi), which is the smallest North American moose subspecies. The Idaho Department of Fish and Game (IDFG) continuously monitors the population to ensure sustainable management.
Idaho’s Moose Population and Subspecies
The Shiras moose is notably smaller than its northern counterpart, the Alaskan moose (Alces alces gigas). A mature male Shiras moose, or bull, can stand up to six feet tall at the shoulder and weigh as much as 1,200 pounds. Despite being the smallest subspecies, the Shiras moose is the largest member of the deer family in Idaho.
Current estimates place Idaho’s statewide moose population between 10,000 and 12,000 animals, a substantial increase from the few hundred present in the early 20th century. The population peaked around the late 1990s and early 2000s, but recent data indicates declines in some areas. Factors such as predation, disease, and the spread of parasites like winter ticks are contributing to localized population decreases, particularly in northern Idaho.
The Idaho Department of Fish and Game manages moose as a trophy species, regulating populations through a controlled harvest system. Monitoring is often conducted using indirect measurements, such as hunter success rates. Scientists have determined that the growth rate of the Shiras population is highly sensitive to the survival of adult females, which guides conservation strategies aimed at maintaining a stable population.
Geographic Distribution and Preferred Habitat
Moose are distributed across more than half of Idaho, primarily occupying the western slopes of the Rocky Mountains. The densest populations are typically found in the Panhandle region, the mountainous areas near the Yellowstone border, and the Upper Snake River region in eastern Idaho. Moose have also expanded their range westward toward Hells Canyon and southward toward the Utah border.
The Shiras moose is a browser, relying on woody shrubs and trees rather than grass, which dictates its habitat preference. Moose thrive in areas with abundant willow thickets, riparian zones near water sources, and high-elevation coniferous forests. Riparian habitats are particularly attractive, providing a rich source of aquatic plants for food and water for cooling during summer.
Seasonal movements are influenced by the need to find forage and avoid deep snow. In the winter, moose often move to lower elevations, sometimes into valley bottoms and developed areas, to access shrubs and brush and take advantage of shallower snow conditions. In contrast, summer often sees them migrating to higher-elevation timbered areas to feed and escape the heat. During the rut, which typically peaks in the first two weeks of October, bulls move down from higher elevations to wetter areas to seek out cows.
Viewing and Safety Guidelines
Moose are generally solitary and non-aggressive unless provoked, but their sheer size makes any encounter demand respect and caution. The most important rule for viewing is to maintain a safe distance, ideally far enough away that the moose’s behavior does not change because of your presence. Never attempt to approach or feed a moose, as this can habituate the animal and lead to aggressive encounters.
Moose are most likely to become aggressive during the fall rutting season, when bulls are competitive, and in the spring and summer, when cows are fiercely protective of their calves. Recognizing warning signs is the best way to prevent a dangerous situation. An agitated moose may lay its ears back, raise the hair on its neck and hips, lick its snout, or lower its head while staring directly at you.
If a moose begins to show these signs, slowly and calmly back away from the area. Unlike with bears, if a moose charges, you should run and try to put a large, solid object, such as a tree or a car, between yourself and the animal. If you are knocked down, the safest response is to curl into a tight ball, protect your head, and remain motionless until the moose moves away.