Here is a few tips:
#1 Press Ctrl and scroll Down. Now you will see that the black area (range of sight) will move backwards. Keep scrolling until it is completely gone.
#2 At the far end of the screenshots depth you see that there is black fog. Black fog at clear day light does not fit. Go to Scenario>Game Options>Options and then check the area named Use Terrain Fog. Check that box and click the two drop down menus (which say "3000" and "5000") and change them to "1000" and "5000". Then change the color to White, Green, Yellow or any other color that might fit a Fall forrest. (recommened is White or Yellow).
#3 Big rocks and trees do not normaly apper "clean". With clean I mean no scrubs, flowers, bushes or anything. When you place big objectives, such as tree, rocks and buildings, be sure to place smaller doodads such as flowers, scrubs, etc, around the big ones.
+ I am very glad that you are making cliffs with the Raise tool! Do not use Blizzard's common cliffs!