This climb is a little scruffy compared to the others in the area. Start on the center of the Southern section of the large slab the lies Southwest of the entrance to the cave. Scramble up that past a slightly dirty start (2 moves) and onto the main slab to the summit line, on mostly 4th class Rock.
The Harmon Flatironette exists as 2 layers of rock. The Front layer houses the Harmon Cave on it's southern end, and lies on top of a second layer. This second layer creates it's own slab to the South of the Harmon Cave, and starts 10 or 20 meters to the Southwest of the entrance. This route starts up the low point of this slab and goes up to the top and then left on the ridge-line to the summit.
Take a standard light rack and a 70M rope - or just scramble it. To descend, scramble down 3rd class rock to the Southwest and then return to the base around the South end of the Rock.