This is one of these images you can't plan, it's impossible to foresee these events, let alone to have them happen in the place you need them to be.
I planned the location, I planned the time hoping for the sun to burst though the clouds and have it hitting the mountain in the background, and I knew it could, because I've been to this location multiple times before, and I knew it could only catch the light like this during summer, due to the mountains blocking the sunset in the fall and in the spring.
But what I could never plan, is the almost perfect rainbow happening almost directly over the mountain as a walked to the location, so i rushed to set up the shot, got one horisontal version to be sure I got something, and after that, I created this pano, created of 8 vertical shots.
And no more than a minute later, the rain came, the sun was gone and everything turned grey..
Fantastic shot. The photography gods blessed you that day and you showed up skilled enough to capture it. Love it.