Idaho’s sprawling landscape, stretching from northern temperate rainforests to the vast arid plains of the south, creates a complex mosaic of ecosystems. This geographical diversity, which includes high mountain ranges and extensive river systems, supports a varied population of wildlife. The state is home to nearly 100 species of mammals, over 200 species of birds, and dozens of species of fish, reptiles, and amphibians. Exploring the animal life of this region requires looking at the distinct habitats, from the towering peaks to the waterways and the wide-open sagebrush steppe.
The Iconic Mammals of Idaho’s High Country
The rugged, forested mountains of central and northern Idaho provide refuge for North America’s most recognizable large mammals. Elk are prominent ungulates, roaming the forests and high elevation meadows, with mature bulls known for their impressive racks and bugling calls during the autumn rut. They share the dense woodlands with Moose, often found near high-country lakes and swamps, where they feed on aquatic vegetation and willow branches.
Other deer species populate the mountain slopes. The Mule Deer prefers the steeper, rockier terrain, and the White-tailed Deer is typically found in the lower, brushier forests and river bottoms. The presence of these large prey animals supports Idaho’s apex predators, including the Gray Wolf, which has re-established populations in the state’s wilderness areas. Wolves play a significant role in maintaining the health and balance of the ungulate herds.
Idaho’s forests are also home to two bear species, the Black Bear and the Grizzly Bear. Black Bears are widespread, foraging for berries and small prey across the forested landscape. The larger Grizzly Bear is found in limited populations, primarily in the northernmost parts of the state, such as the Cabinet and Selkirk Mountains, and is characterized by a distinctive shoulder hump.
Aquatic and Riparian Zone Species
The extensive network of rivers and streams, including the Salmon and Snake Rivers, is fundamental to the survival of numerous aquatic and riparian species. Fish life is diverse, highlighted by the state fish, the Cutthroat Trout, which is highly sought after by anglers in mountain streams and high-elevation lakes. These waterways are also home to the elusive Bull Trout, a species that requires extremely cold, clean water and is an indicator of pristine aquatic conditions.
Idaho is also a crucial destination for anadromous fish that travel hundreds of miles from the Pacific Ocean, such as the Sockeye Salmon and Steelhead. The Sockeye Salmon’s arduous journey to high-altitude spawning grounds, such as Redfish Lake, is one of the longest migrations of any fish in North America. The riparian zones—the vegetated areas immediately surrounding the water—support numerous bird species.
Water-dependent birds include the majestic Bald Eagle, seen soaring over rivers and lakes, particularly during winter when they congregate to feed on fish. Wetlands and marshes host large waterfowl like Trumpeter Swans and Sandhill Cranes, which use these areas as breeding grounds and migratory stops. Among the amphibians, the Long-toed Salamander is widespread, found in moist areas across a range of elevations, while the Idaho Giant Salamander is found in the northern and central parts of the state.
Wildlife of the Plains and Deserts
The southern and western portions of Idaho are dominated by high desert and sagebrush steppe, a vast, dry environment that hosts fauna adapted to warmer and more open conditions. The Pronghorn is a unique mammal of this region, known for its incredible speed and its long-distance migrations across the plains. Smaller terrestrial mammals also thrive here, including the American Badger, a powerful digger that excavates burrows to hunt the abundant ground squirrels, like the Townsend’s Ground Squirrel.
The sagebrush landscape is also home to the Pygmy Rabbit, the smallest rabbit species in North America, which depends on dense sagebrush for food and shelter. The dry, rocky terrain is suitable for a variety of reptiles, including the Western Rattlesnake, which uses its camouflage to ambush small rodents and lizards, such as the Sagebrush Lizard. These desert species possess adaptations, like the ability to conserve water, that allow them to endure the extreme temperature fluctuations of the steppe.
Birds of prey are a defining feature of the open plains, utilizing the vast sightlines to hunt. The Snake River Birds of Prey Area is particularly renowned, supporting one of the highest densities of nesting raptors in the world. Species like the Prairie Falcon and the Ferruginous Hawk are common, with the Ferruginous Hawk preferring the shrub-steppe communities where it primarily preys on rabbits and ground squirrels. The Red-tailed Hawk is also found across these open habitats, utilizing fence posts and lone trees as hunting perches.