Hike up the Royal Arch trail to where the 4th Flatiron touches the trail. Instead of heading directly up towards the high piled cairns, break right (north) around the bottom and do a nasty bushwhack ~200 feet to the base of a slab. The base of the 4th Flatiron will be towering over you on your left (south) and another slab on your right.
From the base of the rock, split 2 trees and head up a sunken section to a split, beneath a small tree, that puts you on the proper face. From here, it is picking the path of least resistance which for me was working up and left towards the well-featured, southern ridge.
For descent, hit the summit and do the easy walk off. There is one step that will make you think twice, but it is short and easy with good holds around.
From here, you can move left (south) to continue up the second section of the 4th or rap off a tree down the corner of the 1st and 2nd section of the 4th Flatiron. Approximately 30m down (1 single 60m rappel), I found an old tipped out piton and very carefully downclimbed/rappelled to a grassy garden area filled with poison ivy. With a single 70m, you could probably reach a great looking Lost Arrow for a rap anchor. From here, one more rap (total of 3) off solid trees and past a turkey vultures lair in the corner of the wall, you're back on solid ground. A quick downhill scramble will funnel you through the cave spiral staircase and back to the Royal Arch trail.
? protection would be similar to other Flatiron east sides, rare. Easy Flatiron slab solo.
The one airy step off the summit.
Looking back down on the base. You can see the 2 ...
Looking back down from the summit. The lowest poi...
Offers great views of the Royal Arch.
If you choose to descend from this sub summit inst...