Yosemite Waterfall may be the most well-known in its namesake park, but each February when the sun and earth align just right, hordes of onlookers flock to watch a red firefall at one of the park's little-known gems, Horsetail Fall.

This marvel of celestial configuration occurs in a flash at sunset in mid-February, if the weather cooperates. In ideal conditions, the setting sun illuminates the ribbon-like Horsetail Fall as it flows off the granite face of El Capitan. The resulting blood-red affectation makes the waterfall appear like it's flowing with lava.

The breathtaking annual phenomenon draws throngs of tourists and sightseers each February to the east end of El Capitan in California's iconic national park. Typically one of the park's little-visited attractions, photographers crane their necks toward the ephemeral cascade for two weeks hoping the sky will be clear.

A chance to see the firefall is rare. The sight lasts just under two minutes and occurs only for about two weeks a year. Furthermore, the southwestern horizon must be clear and the right amount of water must be flowing into the fall. February is the time of year when storm clouds often obscure the setting sun, diminishing the opportunity to see the red waterfall.

This year conditions are good thanks to recent snowfall that's melting and feeding the water stream that flows into Horsetail. Park officials say they hope the good conditions will allow the spectacle to last through Feb. 24, generally the last day of the year it can be seen.

Horsetail is so uniquely situated that I don't know of any other waterfall on earth that gets that kind of light, Michael Frye, who wrote the book The Photographer's Guide to Yosemite, told The Associated Press.

How many are perched on a high open cliff? Most are in an alcove or canyon and won't get the sun setting behind it. Yosemite's special geography makes this fall distinctive, he said.

The fleeting phenomenon materializes in varying degrees of intensity throughout the same two weeks of February each year. It was first captured in color in 1973 by the late renowned outdoors photographer Galen Rowell.

Photographers must account for astronomy, physics, and geometry when considering the right time to experience the wonder. They need to look for the lowest angle of light that will paint Horsetail the colors of an iridescent sunset as rays reflect off the granite behind the water.

Horsetail is often overshadowed by the California park's other famed waterfalls - Yosemite and Bridalveil. Though it's only active during the winter and spring months, Horsetail not only changes color, but holds the record as the longest free-falling waterfall in the park, with a drop of 1,500 feet before it his granite and drops another 500.

Scroll through the photos and view the video below to learn more about this natural wonder.