Chip - yes, just the hill but he tried to incorporate an area after the crest of the hill where the ball would feed down to the green - unfortunately, into the crossbunker - hah
that's a funny hole at ngla - is seems either you love it or hate it (depends on your quirk tolerance, I guess)
OK, so what happened after National - not many true Alps!!
It mostly evolved into what they (really Raynor) referred to as "Alps bunkering" - the full-across, cross bunker, originally with no walkway but as times went on and more manicured bunker sand hazards evolved, walkways were added cutting the crossbunker in half (and in the direct middle, yet - yikes how ugly).
Not many clubs would accept a more or less blind Alps shot so Raynor began to use the crest of the hill as the Alps fairway feature with or without a crossbunker - witness the 12th at Yale, a pretty good example and Jimmy Kennedy has one a fine example at Hotchkiss also.
Later, probably rather than haggling with a club about the hill preceding the green, he began just "simulating" the Alps by using (sometimes just moderate) rises in a fairway with the ball feeding into a punchbowl-style green, not cross bunkered. Lots of variations relative to local topo, of course
There seems to be a lot of similarities between the Alps holes and the PBowl holes - often combined, such as the great one at Fishers Island - perhaps the most picturesque of all of them (Yeah, Donny Beck for running his putting green mowing up the hill as far as he has !!!!!!!!!)
(talking to CB, the old-fart? been accused of it, so might just as well 'fess-up" - can't get a word out of Raynor though and Banks is up in CT near Kennedy)