Roughly the first half of our ride was very tame with most of that portion being on good road, though with some traffic. The latter half was a different story altogether. A short time after leaving Tardets, where we bought bread and had a picnic lunch, we turned west onto D117, a white road that started steeply ascending and just never quit. Our map modestly showed a single arrow for the entire long section of steep climbing. Eventually getting to some col, the name of which I don't recall but which I think said 832 meters, and starting a descent, we were slightly surprised that the road turned back up with plenty more climbing. I'm guessing that we eventually topped out at something well in excess of 1000 meters.
The descent was very steep as well...and long...and with a narrow one lane road that should have had some number of chaussée deformée signs prominently displayed. The map did show the upper portion of the climb as being difficult or dangerous, as there were drops of several hundred meters with no guardrails. At one point as I was looking down, I noted that we were far above a flock of circling birds. The vistas were fantastic.