Very well made. The mountains have great shading with the ridge line through the middle. I do like the representation of trees beside the mountains. Some advice I can think of is maybe varying the tree type to make it a bit more interesting. One tree type that I like to do is a very small isosceles triangle with an even more smaller tree trunk at the bottom.
Click image for larger version. 

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The tree pictured here will be way smaller on the map but it takes some experimenting . This kind of tree also takes longer to make btw, but overall great work!