Two of the images are shown here, and reveal a fairly different park from the one that actually opened. That's not to take anything away from Valleyfair, but it doesn't take long when looking at this art to see the differences. If anything, it seems the park might have opened with a stronger focus on rides, and less on the extensive landscaping and themed structures seen here.
I love when old concept like this surfaces - it's great fun to study the details in the larger images. You can see those and two more pieces of art on Valleyfair's Facebook page.