Grand Prismatic Spring: Boiling, colorful, and full of bacteria! (Yellowstone Monthly Update - July 2025)

Grand Prismatic Spring is the largest hot spring in the US, and one of the largest in the world. The boiling lake was named for the spectacular array of colors along its rim. This month's Yellowstone Volcano Observatory update talks about what creates the colors, along with earthquakes, ground deformation, and hydrothermal activity that occurred in the area of Yellowstone National Park during June 2025.