Rihc,
When you hit the nail on the head with the first reply and it's endorsed by TE Paul what more is there to say??
That certainly was my initial reaction to Mark's question--that Ross did the high to low to high layouts all the time. I've seen it at Oak Hill, Minikahda, Wilmington (where there's not much elevation change but he still did it), and out here in Colorado at The Broadmoor, Wellshire and Lakewood. Tom's right--he did it with topo map in hand, since he didn't even visit sites like Wellshire.
A couple of other thoughts:
--He liked to build smallish, sloping greens
--He built bunkers into the faces of uphill slopes, both in fairways and green approaches. And he would push the greens up on the edges where the bunkers were located and from the drawings I've seen on other sides of the greens too, which makes recoveries more difficult if you're short-sided.
--He liked to build one very long 220-230ish par 3 per course.
These may be more "preferences" than "distinguishing features," but they're things I've seen from playing and studying Ross some.
Rich, I'm wondering how much of Ross's designs emanate from his Dornoch roots. I suspect there are similarities with high to low to high holes there? I've not played it Dornoch so don't know, but I'd be interested in your views...
All the Best,