Rainbow waterfall, in the Devil's Postpile National Monument in the Eastern Sierra (California).
There is a 4 mile hike to reach this waterfall from the Devil's Postpile parking lot. This was during the dry season and during a drought, so the waterfall had little water flowing (and no rainbow!).
For more info about this waterfall, go to en.wikipedia.org/wiki/Rainbow_Falls_(California).
Photos taken in various locations of the Eastern Sierra region, in California.