Mid-June brings the peak activity period for Olympic marmots (Marmota olympus), a species found nowhere else on Earth except in the Olympic Mountains of Washington. These endemic rodents emerge from hibernation in May and spend the short mountain summer feeding intensively on alpine vegetation, sunbathing on rocks, and raising young. Olympic marmots are highly social, living in colonies on talus slopes and subalpine meadows above 5,000 feet elevation. Their loud, piercing whistle calls serve as alarm signals and help maintain colony cohesion. These charismatic animals, weighing 8-20 pounds, are the largest members of the squirrel family in Washington and spend 8 months of each year hibernating underground. Climate change threatens Olympic marmots as earlier snowmelt and changing vegetation patterns alter their alpine habitat, making this endangered species a conservation priority.