Managed to get there 10 min before the start after a 9 hr drive, and it was well worth the effort! For a period of 2 weeks in mid-late February, most years, the Horsetail waterfall at Yosemite National Park glows at sunset when conditions are right.. adequate snow /water for the falls and direct sunlight from a cloudless western sky. Got lucky thanks to friends and family who made it happen!