Olympic marmots are about the size of a domestic cat. They have a wide head with small eyes and ears; stocky body with stubby legs and sharp, rounded claws adapted for digging. Their tails are long and bushy. The coat is double-layered and consists of soft thick underfur, for warmth, and coarser outer hairs. The fur color changes with the season and with age, but an adult marmot's coat is brown all over with small whiter areas for most of the year. Their muzzle is almost always white, with a white band in front of the eyes.
Olympic marmots are native to the Olympic Mountains in the Olympic Peninsula of Washington state, USA. Most of their total habitat is located in Olympic National Park, where they are often sighted, especially on Hurricane Ridge. Within the park, Olympic marmots inhabit lush sub-alpine and alpine meadows, fields, and montane scree slopes. These animals are well-adapted to their generally cold natural habitat, where there is snowfall almost every month of the year on the mountain slopes and barren grasslands.
Olympic marmots are gregarious burrowing animals. They live in colonies containing multiple burrows. These burrows are used for hibernation, protection from bad weather and predators, and to raise offspring. A typical colony consists of a male, 2-3 females, and their young; young marmots stay with their family for within 2 years. Activity of these animals varies with the weather, time of day, and time of year; during summer months because of rains and fogs, marmots spend most of the day in burrows, and forage mostly in the morning and evening. In between these times, they lay on rocks warming under the sun, grooming each other, playing, chirping, and feeding together. Olympic marmots start to enter hibernation in early September. Before hibernating, they bring dry grasses into the burrow for bedding or food. Adults emerge after hibernation in May, and the young in June. When communicating vocally, Olympic marmots have 4 different types of whistles which include flat calls, ascending calls, descending calls, and trills.
Olympic marmots are polygynous which means that males mate with more than one female during a breeding season. These marmots come out from hibernation at the beginning of May, and breeding occurs about two weeks later. Females give birth to 1-6 young in a grass-lined burrow underground after the gestation period that lasts around 4 weeks. Newborn pups cannot see, have no fur, and are pink in color. After a month pups first leave the burrow; around the same time, they begin to be weaned. Even after they are allowed to emerge, the young stay close of the burrow, where they chase each other and fight playfully. Within a few weeks after first emerging from the burrow, the young are fully weaned and can feed themselves. Olympic marmots are not completely independent from their mothers until they reach two years of age. Both males and females become mature at 3 years, but females generally don't breed until they are 4,5 years old.
The main threat to Olympic marmots is human activity and recreation. These animals have a limited geographic range and are protected by law in the Olympic National Park, which contains most of its habitat. Olympic marmots are also preyed on by various terrestrial mammals and avian raptors, but their main predator today is the coyote.
According to the IUCN Red List, the total population size of Olympic marmots is 2,000-4,000 individuals. This species’ numbers are decreasing, however, it is currently classified as Least Concern (LC) on the IUCN Red List.