Looks great and an added benefit will be membership in the 48 Club!!
The only suggestion I have is if you have the room to store it, make the mountain taller and have the train on the second level go through a tunnel as well to hide the shortness of the loop. The portals for this level can be set back from the portals below to follow the incline of the mountain. This basic device was used on some postwar Lionel display layouts