They celebrated Christmas in Yellowstone today - August 25. It's an old tradition among park employees, having little to do with park visitors.
The park mostly closes by Oct. 1, for winter is both long and hard in the Rockies. College student summer employees leave around Labor Day, retiree temps stay a bit longer.
Employees like to share "Christmas" cheer with coworker friends before scattering to the four winds. Thus, celebrating August 25 with Christmas trees, decorations, and the exchange of presents. See Wikipedia about the custom.
