Colorado’s First Fat Marmot Week Puts Chunky Alpine Rodents to a Vote

Colorado’s high-country rodents are getting their own championship bracket. Fat Marmot Week, organized by researchers at the Rocky Mountain Biological Laboratory near Crested Butte, opened voting on August 24 and continues on August 26 and August 28. Eight yellow-bellied marmots are competing in the tournament. Researchers plan to announce the marmot with the highest estimated weight on August 29, followed by the popular-vote winner on August 30. The event takes its cue from Fat Bear Week, the annual celebration of brown bears in Alaska’s Katmai National Park and Preserve. But the contestants in Colorado are smaller, more specialized animals. Yellow-bellied marmots are large ground squirrels that can weigh as much as 11 pounds and grow beyond two feet long. They spend the short alpine summer eating grasses, wildflowers and seeds before retreating underground for winter. Marmots can remain in true hibernation for up to eight months. During that time, their heart rate and metabolism fall sharply, while their body temperature can drop to about 41 degrees Fahrenheit. Unlike grizzly bears during torpor, marmots enter a prolonged hibernation state. The contest comes as researchers report serious concerns about the animals’ survival. According to the Smithsonian Magazine report, nearly two-thirds of one Colorado population died during the most recent winter. Researchers attributed many of the deaths to a lack of snow cover, which normally insulates underground burrows. Colorado’s 2025–26 winter had the state’s worst snowpack on record, and reduced snow also left marmots exposed to predators for longer and affected the wildflowers they eat. The Rocky Mountain Biological Laboratory has studied individually marked wild mammals through its Marmot Project since 1962. The Fat Marmot Week team hopes the event will raise awareness and support research affected by federal funding cuts. The researchers have also used several unconventional fundraising efforts. Their OnlyMarms account shares uncensored but G-rated marmot videos on OnlyFans and has raised about $6,700. A marmot-themed cryptocurrency generated around $100,000 in transaction fees, while Denver Beer Company created a limited-release OnlyMarms Extra Thicc Double IPA and is donating part of its sales to the project.