Several scenes in my final major project are shot from a high altitude, and I’m asking for tips on creating the landscape below the action. I don’t really want to composite landscapes and skies in after the rendering, since the camera will be rotating in a few sections and it’ll be hard to animate a 2D background to the 3D action.
I am using Maya2014, and the main problem I have is how the land meets the sky, I can’t so far, figure out how to make such a thing work, as the camera is so high up off the ground, it can always see the edge of the landscape below it, forming an ugly line on the horizon as can be seen in this concept: 
There is sea in that concept since it was the first thing I could come up with that almost fixes the issue. However in the actual animation, the events will be inland. Does Maya have a 3D skybox feature like the Half Life 2 engine? Or is there any other features or tricks I can use to make a nice landscape, without the use of impractically huge polyshapes?
Oh also, I know I’m saying high altitude, but before anyone suggests a scene made entirely of clouds, the altitude isn’t that high.
Thanks!