ApproachThe Fifth Flatiron is the southernmost and last of the numbered flatirons. Its elegant, pointed shape is visible from many points in Boulder. It is characterized by the aplty named Cat Scratches--a series of deep cracks/chimneys that furrow its east face.
Four routes to the summit of the Fifth Flatiron are described in guidebooks, all on the east face. Besides the object of this page, one line with many possible variants follows the cat scratches, and two stay further right (that is, north). The Fifth is a lot less frequented than the first three flatirons; while the climbing is technically quite similar to that encountered on the slabby east faces of its more popular siblings, the experience is rather different. The slightly higher elevation also implies that snow lingers a little longer: something to take into account in winter and spring.
To reach our route, start from the Chautauqua parking lot and walk along the fire road to the Bluebell Shelter (0.75 mi). From there, follow the Royal Arch Trail to its end at the Royal Arch (0.9 mi). Once at the Arch head up west on a very faint climber's trail, which goes around a flatironette on the left (south). In a few minutes of mild bushwhacking you reach a rather level opening at the base of the Fifth, from which you have a good view of most of the face. This opening is near the southern edge of the face, and is where the climbing starts. The very faint trail continues to the left, providing the standard return path from the summit.
Route DescriptionP1: Climb straight up for almost 60 m (200 ft) until you meet a large crack that rises at first vertically from the base of the east face and then crosses diagonally to the southern edge of the face. As the crack approaches the edge, it widens and forms a couple of niches that are suitable places for belaying. Difficulties up to 5.4 on featured sandstone, which, however, does not offer many placement opportunities.
P2: Cross the crack, climb a short headwall, and continue for less than 40 m (130 ft) to a comfortable belay stance. The start is 5.4 and the rest is easier.
P3: Aim for the summit for a short pitch and belay at a large ledge about 20 m (70 ft) below the summit. The start is 5.4 and the rest is easier. With a 70 m rope you can combine this pitch with the next and reach the summit directly.
P4: From the ledge angle right and attain the spectacular north ridge. Follow the ridge to the summit , where you will find an eyebolt, a couple of bolts, and even an old piton. The difficulties are modest (maybe 5.2), but the exposure and the elegance of the sweeping ridge make this pitch one that you don't want to miss.
Total length of the climb: about 550 feet.
Descent: Rappel to the west from the summit for about 23m (75 ft). From the base of the rappel, hike up and south to reach a very steep and slippery climber's trail that contours the south side of the flatiron and takes you back to the base of the climb. From there, retrace your steps to the Royal Arch, and from there follow the trail to the trailhead. Do not try to go down on the north side of the Fifth Flatiron unless you enjoy extreme bushwhacking.
There is also a downclimbing option. You can find a description on Mountain Project. I haven't tried this downclimb, and hence I don't have an opinon on it.