So lovely!
I would post-process it like this. Though, I am not sure how much it looks like what you saw in real. Graduated density filters (either physical or in post processing) help a lot when the sky is so bright that makes foreground underexposed.
Could spend some more hours on that photograph, nice shot.
Here’s my attempt in Filmulator:
Drama and Overdrive were raised to the max, with Film Area reduced in order to make haloing less visible.
Then the White Clipping Point was brought way down to brighten up the image, and the Shadow Brightness decreased a tad and Highlight Brightness maxed out in order to add contrast.
Great image! Here’s a take on it using Filmic RGB and the Tone equalizer (lifted the “foreground” tones quite a bit). Also some saturation and local contrast added.
DSC00128.ARW.xmp (14.9 KB)
Nice photo.
Within RT I’ve menaged to reach the right exposition and, according to your wish - “The leaves had different shades of red, yellow and brown. The lake and the sky had a nice blue color. And the mountains in the background were more clear and distinguishable.” In any case, somehow 
On the location: It’s Kochel. The view is from the way up to the Herzogstand (I assume) down on the Walchensee.
Kochem, nowadays Cochem, is a town near the Mosel in Rheinland-Pfalz 
Here is my conversion. RT dev, Auto matched curve, Highlights/Shadows and a little bit of saturaion, not too much to prevent the green/brown of the spruces from getting too poisonous.
DSC00128.jpg.out.pp3 (11.6 KB)
You are right it is Kochel. Thanks for pointing it out.
@flannelhead welcome aboard…nice job getting the trees in the foreground to pop without making the colors unnatural.
