Horsetail Fall is the Yosemite waterfall known for a temporary “firefall” effect when sunset illuminates its February flow.
The waterfall drops from the eastern side of El Capitan in Yosemite National Park. In late winter, if snowmelt supplies enough water and the sky is clear, low evening sunlight can make the narrow cascade glow orange, creating the appearance of molten lava. The phenomenon is commonly called the Horsetail Fall firefall.
The effect is not guaranteed: it depends on water, weather and the precise angle of sunlight. It is also different from Yosemite’s former man-made Firefall, a historic spectacle in which glowing embers were pushed from Glacier Point. Horsetail Fall itself is a natural seasonal waterfall, and its flow may disappear outside the wetter months.