...I am actually going back tonight to get a shot with more dynamic clouds.
Take a flash fitted with a snoot, zoom the head to its tightest spread and hit it on the camera left side. Don't blast it so it looks ackward with the direction of the setting sun, but enough to add some pop. As is, it is featureless for being the subject of the image. If you can't get an OCF there, use a small reflector to accomplish the same.
Awesome location find. It could take many, many trips there to get the right combination, but it would be worth it IMO. If your child(ren) are of an age that fits the scene, make him/her stay up past their bedtime. Borrow a kid if you have to, but I think you'd have a greater impact for the scene. It begs for a person to be in it.