Update

Uploaded a brand new, built from ground up (I generated new texture maps) a 2048 pixel version. This is quarter in size (4-5mb) of the 4K version, and yet almost gives as detailed stones and mountains as the 4K. This took me a few hours to figure out how, but see the images and try it out for comparsion. I actually like this version better, I've been play testing it for a few hours.
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4K textures for mountains, It's only 4 texture files. They are custom made by me with a texturing software. Good midrange video card (GTX 660 or ATI7770) or better recommended. Other modders free to use these textures, but just mention my mod here in yours.