Yosemite National Park is in California's Sierra Nevada, about three hours east of the San Francisco Bay Area.
The weather and the water flows often don't cooperate. Snow must be present in enough quantity above El Capitan, temperatures need to be high enough during the day to melt the snow and make the waterfall flow, and the sky must be clear in the last 10 minutes of daylight for hte setting sun to illuminate the water.
Horsetail Falls backlit by the setting sun in Yosemite National Park, California. This was an amazing spectacle to witness. Happening only two weeks out of the year, the setting sun falls behind the vertical face of El Capitan, selectively lighting this waterfall with its orange sunset light.