Yellowstone Insider Your Complete Guide to America's First National Park

Giant Geyser is the central geyser of the Giant Group, which includes Mastiff Geyser and Bijou Geyser. In a “normal function eruption,” only Giant erupts, which means it will usually be shorter in terms of time and plume size, attaining 150 feet. Meanwhile, during a “Mastiff function eruption,” where Mastiff erupts alongside Giant (and sometimes Bijou), making Giant rocket upwards of 250 feet. Giant Geyser has had a long history of amazing visitors and explorers alike—not only for the size of its eruptions, but also for its marvelous geyserite cone. The quick sketch above, done by Walter Trumbell of the ...

A viral video shows a tourist petting a Yellowstone National Park bison, but despite the uneventful outcome, officials warn that Park wildlife is still dangerous, and an approach like this could be deadly.