The shape is based on a landscape mesh with displace modifiers. The textures used here are based on photos I took in Norway and control displacement modifiers and material shader mixing (rock-snow). Much of it is based on tutorials I've watched over the years (this one on Sardi Pax's in particular). The snow is simply a white diffuse shader with some blue subsurface scattering and could be improved with image texturing. The compositing node-setup includes DOF, which is turned down for the rendering of the preview but may come in handy (I will use it for a cinematic sequence). Hope you enjoy it.