MAMMOTH, Wyoming - In Yellowstone National Park near Mammoth, WY, New Blue Spring is a hot spring in Mammoth Hot Springs and visible along the Mammoth Hot Springs boardwalk between Mound Terrace and Upper Terrace Drive. Here, the ~170^oF water meets the chilly 35^oF air, creating a fine mist over the water. This thermal feature is just one of the collection of more than 10,000 hydrothermal features – including 500+ geysers like the famous geyser, Old Faithful – found within the park's 2.2 million acres.