The Upper Geyser Basin has the highest concentration of geothermal features in Yellowstone National Park. This complement of features includes the most famous geyser in the park, Old Faithful Geyser, as well as four other predictable large geysers. One of these large geysers in the area is Castle Geyser which is about 1,400 feet northwest of Old Faithful. Castle Geyser has an interval of approximately 13 hours between major eruptions, but is unpredictable after minor eruptions. The other three predictable geysers are Grand Geyser, Daisy Geyser, and Riverside Geyser. Wikipedia
Crested Pool is a hot spring in the Upper Geyser Basin in Yellowstone National Park. The spring is 42 feet deep. Adjacent to the Old Faithful Inn, the spring is named for the "crest" which surrounds the pool. Although it is considered a spring, Crested Pool sometimes erupts like a geyser. Wikipedia
Cascading from the 590,000 year old Canyon Rhyolite lava flow, Lower Yellowstone Falls is the largest volume waterfall in the Rocky Mountains and are 308 feet high, or nearly twice as high as Niagara Falls. The volume of water flowing over Lower Yellowstone Falls can vary from 680 cu ft/s in the autumn, to 8,400 cu ft/s at peak runoff in late springtime. The flow rate of Lower Yellowstone Falls is much less than that of Niagara Falls, as the Yellowstone River is only 70 feet at the point at which it goes over the lower falls. Wikipedia
