Donald, I always thought that you were keeping the images that dark from a stylistic standpoint. What is the output level of your screen set to? The recommended output should be in the 80 - 120 nit (candela / square meter) range. If your machine's output is set to the standard "office environment" setting of 200 - 600 nits, these image would look quite different to you than they do to me. I'm running my screen at 110 nits.
If I had edited this scene, I would have left the endpoints where they are and shifted the gamma to give me an image that looks like this:
Here I get good definition in the rocks and the lighting is still moody.
One quick check if you don't have a screen hardware calibration device is to set up your screen with a white image. If you set your camera up to get just the white, 100 nits is when your camera's light meter shows a correct exposure of 1/30th sec at f/6.3 at ISO 200.