The course is at the base of Jackson Hole Mountain Resort near Teton Village. Anyone who has been out that way would state that most of land between the resort and Wilson is flat. Mostly old caw pastures. There's a great book on the topography of Wyoming called "Rising From the Plains" by John McPhee that describes how the Snake River bed is about the flatest area you'll find in the state, despite being yards from some of the most rugged mountains this side of Nepal.
I'd venture Fazio and crew moved quite a bit of dirt to create the course, including the mounding and requisite lakes. Teton Pines down the road was built on similar terrain, but looks and plays like its on the salt beds of Utah.
Not mountain golf, but certainly mountainview golf.