This site is covered on page 74 of my new guidebook "Photographing California Vol. 2 - South". I just received my first box, and started shipping author-signed copies yesterday!
In the same way that the sun can make rainbows appear in the mist of waterfalls during the day, the full moon can make rainbows appear in the mist of waterfalls at night. On one hike back out from this remote location, we encountered a bear, several deer, and eyes hiding behind the overhanging branches of a pine tree, probably a coyote or bobcat.
As photography increases in popularity and the most obvious sites and events get more and more crowded, you have to hunt a little harder to find something really cool and unique. But it is still possible, and you don't have to fly to some remote country to do it! I had a suspicion that a lunar rainbow or "moonbow" might be possible here, so I checked maps and moon angles to identify the best dates and times. When I arrived and found a good vantage point, sure enough, there it was!