Good creation. I like Terragen too. Got one due to be uploaded about now. Nice natural landscape structure and the surface maps are well layered. The water transparency allows the snow just below the water level to be slightly visible. Good touch. Although it looks nice, I might have gone for a different white balance level (photographically) that would match the atmospheric light scatter in the reality of a cold clean environment. i.e. adjust the 'light delay / red' levels towards a blue, colder feel. Just an idea, as I'm right in the middle of a Terragen session. Thanks for the render!!
Good angle and Pov. Def like the way the clouds are working with the sun. Give the scene a nice light but maybe try and drop down the sun a hair to bring out a few more shadows. The snow, although maybe a deep snow seems a bit to flat, might try and ad a few small hills to it.