"Horsetail Fall flows over the eastern edge of El Capitan in Yosemite Valley. It's a small waterfall that many people don't notice, but it has gained popularity as more and more people have noticed it can glow orange during sunset in mid to late February.The most popular place to see Horsetail Fall seemingly afire is El Capitan picnic area, west of Yosemite Lodge and east of El Capitan (see map below). The ""firefall"" effect generally happens during the second half of February. A clear sky is necessary for the waterfall to glow orange.Photo: Bethany Gediman, NPS"