Modder ‘luxor8071’ released a new texture pack for the Special Edition of Skyrim. According to its description, the Landscape Overhaul HD replaces all landscape textures with new highly detailed 2K textures.
This mod also includes luxor8071’s Glacier 4k and Real Snow HD mods, as well as riften leaves dirtcliffs, roads and high-quality LODs. The modder has not included any mountain textures, however he suggests downloading either Majestic Mountains or his Natural Mountains and Rocks 4K mod.
Those interested can download the mod from here, and below you can find some screenshots showcasing these new textures!