For now, let me send you one of my original files I've been trying to work on:
Dropbox - IMG_0725.CR2
That's a amazing photo; that is not the planet earth I know.
First a comment about what you did behind the camera. You set a -1 exposure comp when you took the photo. That did a lot of harm. You had already notched up the ISO and that -1 EC is just like raising the ISO another stop up. So your raw file is underexposed and a bit noisy. Let's look at that issue a bit more using the camera JPEG.
That's the camera JPEG with an inset histogram. Notice how far the histogram is from the right corner. The camera JPEG is both underexposed and flat. You had the camera picture controls zeroed out and the camera set to Faithful.
I put the CR2 file into DPP which permits making a new JPEG simulating the camera picture controls. I changed the setting from Faithful to Landscape, removed the -1 EC, and increased the contrast setting to +3 -- Here's that JPEG:
It's better but the histogram indicates blown highlights. Both the blue and red channels are blown in the JPEG. But I'll bet the CR2 file would have been OK and with the added exposure in fact much better. Shooting for raw files is like playing a game of chicken. The more exposure the sensor gets the better the raw file gets as long as you don't clip the sensor's threshold. In this case if you wanted to hedge your bet (chicken) a -.3 EC would have more than sufficed. It's hard to make a recommendation about the best way to go here. You're taking photos that you can't re-stage and take again and the problem with playing chicken is eventually you're going to lose.
So here's my take on your photo using Adobe:
Histogram:
And here's the processing for you to examine:
IMG_0725.xmp
Copy the XMP file into the folder with your CR2 file and LR will show you what I did. Have to give my wife some credit for this. She was likewise amazed by the photo and the first thing she said was, "Wow! National Geographic." Then as I was adjusting it she said, "You're going cartoon on it -- leave it alone." And that reaction I'm sure tempered me a bit.
Some notes: First problem was white balance. You had the camera set to daylight. There's nothing in the photo that can be used as a white balance reference and I have no idea what color that landscape really was but there is a clear blue sky and my understanding of geography tells me you're higher up than sea level. So I set the temp value to 5700, but I wouldn't be at all surprised if it was really up above 6000. Then I adjusted the tint value until I got blue sky. This I did by the numbers. The final photo for internet publication is assigned the sRGB color space and in the sRGB color space daylight blue sky has a hue value of 211. So I set white balance to reach that target. Otherwise the daylight white balance setting left the sky horribly cyan.
No harm in letting Adobe take a crack at the tone response so I went ahead and clicked on auto to get started. One thing Adobe will do in that case is get pretty close with the white and black clipping points but Adobe always overshoots the exposure value. So I pulled back the exposure and manually fine tuned the clipping points. Throughout the process then I keep going back to the white/black clipping points and re-adjusting as needed after making other changes. The last step as always was to re-check the clipping points.
The sky was too light and hazy in the distance. I used a gradient to adjust that and both darkened the sky and raised contrast. The sky lightens and shifts color to the left corner. I used a 2nd gradient to suppress that. I applied a slight vignette.
I raised the contrast of the entire image, and pulled back on both highlights and shadows some.
This is a photo of the horses. But they are in shadow and the bright sun on the middle ground in front of them takes away the attention they should receive. Got to fix that. So you'll find 3 different adjustment brush masks in the foreground of the photo. One suppresses that bright sunlit section. Another lightens the horses and lightens the dust clouds they're kicking up. The 3rd reduces saturation over the foreground. I raised the contrast in the photo a lot which helps with the distant haze but increasing contrast increases saturation and the foreground was starting to go overboard. There is also a gradient on the foreground right at the bottom to darken the bottom edge.
I made changes in the HSL panel. I further darkened and saturated the blue sky and the foreground yellows had a green tint that I didn't like so I shifted that a little.
And finally I applied a little noise reduction.
A last thought: because there's a bit of noise from the underexposure another technique that I often use that works well is to add some simulated grain and it's worth trying that in place of the noise reduction.
Joe