Which marmot is native to Washington state's Olympic Mountains and hibernates deeply?

The marmot native to Washington state’s Olympic Mountains is the Olympic marmot.

The Olympic marmot (Marmota olympus) occurs only on Washington’s Olympic Peninsula, especially in subalpine and alpine meadows of the Olympic Mountains. About 90% of its habitat lies within Olympic National Park, where the species is protected and is often seen in places such as Hurricane Hill.

Olympic marmots live in colonies and dig burrows for shelter, raising young and surviving winter. They are social animals that communicate with several kinds of whistles, and their colonies can range from a single family to groups containing as many as 40 marmots. Their diet consists mainly of meadow plants, including grasses, lilies, lupines and other flowering species.

The name can cause confusion because several marmot species inhabit western North America. The Vancouver Island marmot is another regional species, but it is native to Vancouver Island in British Columbia, not Washington. The Olympic marmot was declared Washington’s official endemic mammal in 2009, emphasizing how geographically restricted it is.