Although Alexander’s chimney can be climbed as a summer rock/moss climb, sane people think of it as excellent early season ice route. In most years, Alexander’s chimney offers an amusing romp up moderate ice with a few scrappy sections of mixed climbing. Overachievers can connect this route with one of the multitude of routes that sprout from the “Broadway” ledge for an exhausting day of mountain fun.
From the Longs Peak ranger station, hike along the main trail following the signs towards Longs peak. The wise will leave very early from the parking lot. After four miles, and above tree line, the trail forks with the right branch leading to the Boulder field and the left towards Chasm view lake. Follow the left fork towards Chasm view up and over the lower flank of Mount Lady Washington and toward the Diamond. The Diamond will be clearly visible from the trail beyond Mount Lady Washington. In most years, a boot track will carry you from the parking lot to the Chasm View ranger hut. Climb up and over the terminal moraine directly behind the Chasm View Ranger hut, scramble down towards the lake. If the lake is well frozen, the most efficient route is along the South (left) flank of the lake. Otherwise, you will have to scramble through the poorly marked trails on the talus slopes that guard the North (right) edge of the lake. After passing the lake, make your way to the south (left) edge of the valley and work your way uphill towards the large snow slope that runs along the flanks of the Diamond and uphill towards Mount Meeker (Lamb’s Slide). Kick steps uphill along Lamb’s Slide until you reach a distinctive ice choked chimney. If you reach the ledge that bisects the Diamond (Broadway) you have gone too far.
Pitch 1: Romp up the short ice steps that guard the start of the route and pull onto a lower angle ramp above. There are numerous spots to belay along the right wall (WI 3).
Pitch 2: Move the belay up the gully to an appropriate spot below the giant chockstone (WI 2).
Pitch 3: Climb up the ice smear underneath the chockstone and look for the secret hook placement (and #2 Camalot) behind the upper left edge of the chockstone. Scratch through the thin ice along the left edge of the chockstone and balance trough a few mixed moves onto better ice above. Belay at a series of fixed anchors up on the left before things start to look hard (WI 4, M4).
Pitch 4: Climb the small ice pillar (if you are lucky) or weird mixed ground (more likely) towards a small right tending ledge system. Belly flop/squirm your way over the narrow ledge up towards the detached “flake o’ death” and relax. Continue above the death flake in a small right facing dihedral past a fixed ice specter towards salvation above. There are numerous spots to build an anchor after you reach Broadway (WI 4, M4).
For more fun, continue up one of the mountaineering routes to the summit of Longs or traverse over to the Window (WI 5, 5.9) for maximum fun. More sane people can rappel the route or traverse out along Broadway back towards Lamb's slide for an easy down climb. If you plan to traverse out via Broadway, you will want to go behind the huge pillar visible (above and to the left of you) from your last belay.
Beware, there are many places in the Longs Peak area that are exposed to serious avalanche danger. The ranger’s hut at Chasm view Lake was destroyed a few years ago by a huge avalanche that originated in the Loft (a long way from the hut). Lamb’s slide is also notorious for avalanches. This should be kept in mind with all of the standard dangers (rock fall, fast moving storms, evil marmots, etc.).
Here is a story of some climbers getting avalanched off of Alexander's Chimney: http://nsidc.org/snow/avalanche/survival.html
2 ice tools
4-6 ice screws
Selection of nuts
1 60 meter rope (two if you plan to rap)