Get ready for a little Christmas in July: There’s a new baby blue pool in Yellowstone National Park, and science suggests it started forming on the winter holiday.

Yellowstone geologists find a 13-foot-wide milky blue pool near Tree Island in Norris Geyser Basin, likely formed by small hydrothermal explosions on Christmas.

A routine temperature check at the Norris Geyser Basin in Yellowstone National Park led geologists to discover a new blue water spring.