Craig Pass Closed for the Season; Mammoth to Norris Closed Sept. 14-30
The road linking West Thumb and Old Faithful is closed for the season—traffic should detour through West Thumb, Lake, and Canyon. The road from Mammoth to Norris is closed for two weeks—traffic should detour over Dunraven Pass. More »
Many of Norris' features release acidic water. Amazingly, living organisms thrive even in the extreme environments of these acidic hot springs! The overflow channels of geysers and hot springs are often brightly colored with minerals and microscopic life forms. Hardy, microscopic, lime-green Cyanidium algae thrive in these warm acid waters. Orange cyanobacteria may be found in the runoff streams in Porcelain Basin. From a distance, these bacteria look like rusty, iron-rich mineral deposits.
These and other microscopic life forms are links to the emergence of life on earth billions of years ago. They are also a focus of research in the fields of medicine and criminal investigation. New tools for use in such complex areas as AIDS research and DNA "fingerprinting" have been developed from the microscopic thermal organisms found in Yellowstone's hot springs.
Did You Know?
Lake trout are an invasive species of fish that is decimating the native cutthroat trout population in Yellowstone Lake.