Since 1963, Breckenridge has thrown a December party for Ullr, the Norse god associated with snow and skiing. The festival was the idea of Trygve Berge and Sigurd Rockne — Norwegian locals among the founders of the ski resort — who modeled it on European winter carnivals, and it has run ever since, making it one of the oldest continuously running winter festivals in Colorado.

The centerpiece is the Ullr Parade down Main Street, famous for irreverent floats: ski-mounted hot tubs, Viking ships on wheels, all competing for prizes. Then there's the signature stunt, the world-record shotski. On December 13, 2024, 1,401 people lined Main Street along 503 linked skis stretching 2,477 feet to reclaim the unofficial record. A bonfire and the crowning of Ullr royalty round out the traditions.

The 62nd festival ran December 18-20, 2025, with the 63rd set for December 17-19, 2026. Everything is free.