At least not all that compared to other climbs in the Unknown Coast ride that you don't hear about as much. Panther Gap Ridge is, by some reports, 6.8 miles of a 7% grade. The Wall is only one mile of whatever that silly 18% - 22% business is. Might blink and miss it. Though it looks like the Wall is there to protect the next big hill from invading hordes. As soon as you drop over the wall, there's a much bigger if less severely steep hill. And that big hill is at the very end of the ride.
I plotted the whole ride on Bikely just so I could get a better picture of what to expect.
I think the key here will be to ride in super energy saver mode. No displays of machisma, no hurry or unnecessary effort, no pedaling downhill, plenty of stretching at rest stops, plenty of Gu or Clif Shot, plenty of fluid...as Jennifer Stone used to say on her program "Stone's Throw" on KPFA when I listened in Berkeley / SF, "Go easy, and if you can't go easy, go as easy as you can."