The Eastern Groundhog, also known as the woodchuck (Marmota monax), is not native to Oregon. Although it is a member of the squirrel family, this species does not naturally occur within the state’s borders. The confusion often arises because the groundhog is one of 15 different species belonging to the genus Marmota, the group of large ground squirrels. While M. monax is absent, Oregon is home to its own distinct native species of marmot.
Clarifying the Groundhog Question
The common name “groundhog” is reserved for the species Marmota monax, which is distributed across the eastern and central United States and Canada. This species prefers lowland, open country and forest edges, where it is known for its extensive burrow systems in fields and pastures. Its range barely touches the western edge of the continent, extending only as far south as northern Washington state.
The marmots found in Oregon are entirely different species, despite belonging to the same genus Marmota. All marmots are large, stocky rodents adapted for digging and hibernation, but they are genetically and geographically distinct. Oregon’s species are alpine and subalpine dwellers, preferring mountainous terrain in contrast to the lowland habitat favored by the Eastern Groundhog. Therefore, any sighting of a large, whistling ground squirrel in Oregon is not the woodchuck of Eastern North America.
Oregon’s Native Marmots
Oregon is home to the Yellow-bellied Marmot (Marmota flaviventris), the primary marmot species established within the state. This animal is the largest member of the squirrel family in Oregon, characterized by its short, stout legs, bushy tail, and a robust body that can weigh up to 11 pounds. Its coat is a mixture of brown, gray, and black, but it is identified by the distinct yellowish or reddish-yellow fur on its belly and chest.
Yellow-bellied Marmots are nicknamed “rockchucks” or “whistle-pigs” due to their habit of sunning themselves on rocks and emitting a sharp, loud whistle as an alarm call. They are true hibernators, beginning their sleep as early as late July or mid-August to conserve fat reserves through winter. They typically emerge from their burrows in late February or early March, with adult males appearing first to establish territories before the females follow.
A second species, the Hoary Marmot (Marmota caligata), is sometimes mentioned, though its established population is generally north of the state in the high Cascades of Washington. The Hoary Marmot is a larger animal, known for its thick, silvery-gray fur over its head and shoulders, which gives it the “hoary” appearance. This species is structurally adapted to the highest, most rugged alpine terrain.
Where Oregon’s Marmots Live
The Yellow-bellied Marmot inhabits the eastern slopes of the Cascade Range and eastward across the rest of Oregon. Their distribution generally occurs east of a line connecting landmarks like Mount Hood and Mount Mazama. These marmots require specific habitat features, primarily consisting of rocky areas, talus slopes, and boulder piles that provide shelter and protection from predators.
Their preferred environment is subalpine and high-desert terrain, where succulent vegetation is available for grazing close to their rocky dens. They are rarely seen in urban or valley areas, instead occupying the drier, high-elevation, and mountainous environments across Central and Eastern Oregon. The Hoary Marmot, if present, would be limited to the highest, most northern alpine peaks of the Cascade Mountains, living strictly above the tree line in rocky, tundra-like conditions.