A correction:
I wrote:
12th 640 tip, 600 front of back tee, any yardage from 640 to 470
Actually, the whole long ramp is not kept mowed to tee box height (but could easily be.)
The back (blue) platform goes from c640 to c615. The next (black) platform resumes at c575 to about 540. I forgot to measure to the next (white) platform, but it's about 510 to 470. The original tee box, just off the 11th green, remains. The "new" tee was first built in 1958 and tipped at about 540. The newest tees have extended this back to 640, and the whole set have been slightly re-directed.