This is a line that winds up mostly on distinct terrain from the other 4 lines on the East face of the Fifth Flatiron described in Rossiter's Rock Climbing the Flatirons and/or Haas' Climbing Boulder's Flatirons. After looking at the start of East Face, North Side, 5.4 (Regular Route), this looked more interesting and protectable. It follows a left-angling, double crack/groove system, connects to a series of right-facing flakes, and finishes by bouncing between other lines on the face.
P1. Start up the double crack/groove system just to the left of the 3rd chimney (counting from the right). This is between Cat Scratches and East Face, North Side. At ~95' up, the features to the right draw you, but you head back left when you find few face holds and want additional protection. At ~140', you can move left of the cracks/grooves onto featured face holds. You can get a belay at a small stance at the start of the right-angling flakes, 5.6 PG-13, 195'.
P2. Follow the right-angling flakes aiming for some trees near the right edge of the face. There is a healthy runout early in the pitch. Then there is a funky spot with a sort of undercling/lieback on rounded features with smears for the feet (crux). Finish up a good ledge with a small tree (right) or crack/flake (left) merging briefly with East Face, North Side, 5.7 R, 185'.
P3. This is a fun zig-zag pitch. From the belay, there is a traverse left avoiding the obvious arete above. After ~45', head up on featured face with intermittent protection. Short of the arete above, traverse left, then make a short zig back up to the arete for a nice belay at a notch in the arete with a good, horizontal finger crack, 5.5, 200'.
P4. Trying to avoid the arete above, angle leftwards below the arete starting 5 feet below and finishing perhaps 25 feet below the arete. This probably crosses the East Face South Side or Left as it ultimately finishes straight up to the top, 5.5 R, 145'. The anchor here is a big eyebolt, piton, pop-top type 1/4" bolt, and a 1/4" Star-dryven bolt.
Rappel 75' off the top.
Funny, this may be the fifth route on the East Face of the Fifth Flatiron.
This follows a left-angling, double crack/groove system, connecting to a series of right-facing flakes, and finishes by bouncing between other lines on the face between Cat Scratches and East Face, North Side... and probably crosses East Face South Side or Left.
Wires, a few hexes, cams #0 TCU to #4 Camalot. An extra yellow TCU or two is nice.
Deb on P1.
The surprise up near the top.
Deb up near the crux, P2.
Deb on P4.
Deb near the start of P3.
Topo drawn on Charles Danforth's photo.