Horsetail Fall, a waterfall in Yosemite National Park, occasionally appears to be on fire due to the reflection of the sunset in the waters of the falls. This is a completely natural phenomenon, and there is a degree of luck involved with whether park visitors will actually get to see this event occur. As a natural event, factors such as weather may impair or obscure the view or effect, but there is a higher chance of seeing the seemingly flaming Horsetail Fall light up in the last half of February.
There is another fiery waterfall in Yosemite's history, though it was a man-made occurrence. For about 100 years, an official event consisting of a "firefall" took place at the park on summer nights. The Yosemite Firefall was a non-natural event in which employees from the Glacier Point Hotel would dump burning embers down the side of one of the park's cliffs, giving the appearance of a flaming waterfall. The practice was discontinued during the 1960s because it distracted from the natural features in the park and caused some damage to the plant life in the viewing area.