I think the Bulgers must have cast a shoe riding their Top 100 horse when they decided to add this peak to the list. I have contemplated many scenarios as to why they decided to do so. But until I get the definitive answer from one of them, I will have to be content with conjecture. The peak has very little prominence (80 ft), and, to be fair to actual peaks, isn't even a peak. Instead, it is merely a crag--the highest point on the aptly named Ripsaw Ridge. The peak, er crag, is a quarter-mile west of Mt. Buckner's summit. Both summits can be done in the same day. Horseshoe requires a little bit of roped climbing (half-a-pitch). Buckner is a walk-up (Class 3).
Also, the crag that is known as Horseshoe Peak isn't actually the historical Horseshoe Peak. The historical one (what I will call the "True Horeshoe" or "Real Horseshoe") is the twin-spired formation with a U-shaped notch at the center of Ripsaw Ridge. The "Bulger Horseshoe" only came into existence when a cartography mistake erroneously placed the Horseshoe Peak label at the Bulger location. For more info, see this picture and the responses beneath it, this picture, and specifically this picture.
Unless you're a Bulger Top 100 enthusiast there's not much reason to climb this peak. However, since I have some good representative photos, I thought I'd add it here. Never has this crag been so lucky.
There are two standard approaches to this peak. It can be done in a very long day but it is better served as a two-day jaunt. The first approach is by way of Sahale Arm. The second, which is more direct but requires more elevation loss and regain, is by way of Lower Horseshoe Basin. To get to the trailhead (Cascade Pass Trail), drive to the town of Marblemount via Hwy-20 and refuel and/or pick-up any last minute supplies at the convenience store. From the main corner in town, drive east on Cascade River Road for 22 miles to the trailhead (3,600 ft).
Approach 1: Sahale Arm
Make the standard approach to Sahale Arm (on Sahale Peak). Since that page's description for that approach is woefully inadequate, I will elaborate here. Hike the interminable and way too low-grade Cascade Pass Trail for 3.7 miles to the 5,400-ft pass. Cuss at will at the fact that the trail takes so long to go nowhere. From the pass, find a trail (look for a sign) that leads northward up onto Sahale Arm. In about 2 more miles the well-worn trail arrives at ample campsites near the toe of the Sahale Glacier (c. 7,600 ft).
From camp, hike eastward until the terrain begins dropping down into an obvious drainage of the SE toe of the glacier. Turn right before the drainage and hike southward on its western fringe for a couple hundred yards, passing a snowfield (if late season) on its west. You will drop down a couple hundred feet or so to do this. Once at the level of the bottom of the snowfield (c. 7,200 ft), turn left (east) again to walk below it on nice slabs. Continue westward down a slabby ramp until it is feasible to turn right again so you are facing SE. DO NOT CROSS THE PROMINENT STREAM. Descend easy slabs for several hundred more feet until the slabs give way to talus. There may be some routefinding down these slabs but it should be no harder than Class 3 with minor Class 4 steps. The talus starts at 6,800 ft.
At about 6,700 ft or where most feasible between the waterfalls above and below, cross the stream. But before you do so, look at the rocky rib on the other (east) side. Notice how it comes to an end at some trees and a notch. A little farther down (maybe 200 ft to the right), there are some scrub evergreens just before the rib cliffs out even with the lower waterfall. HEAD FOR THOSE SCRUB EVERGREENS. There is a hidden gully/ramp there which greatly reduces the amount of downclimbing necessary to get into Horseshoe Basin.
The gully/ramp is a narrow dike (approximately 8 feet wide) that drops about 100 feet on the Horseshoe Basin side. The dike starrts out Class 3. A short downward Class-4 step then gets one to an alcove with mining equipment stashed in it. The remainder of the dike is Class 3 but somewhat exposed and loose.
Once in the basin at 6,600 ft, contour northeastward then eastward on slabs below the Davenport Glacier. Pass an old mine just beyond the east end of the glacier. A 6,900-ft rock promontory in the middle of the basin (good camping) should be passed on its high side. Basically, you want to hug the rock wall of Ripsaw Ridge as best as possible. When the rock wall ends at an ice-filled depression just before Mt. Buckner (c. 8,000 ft), you are now near the foot of Horseshoe Peak. But which crag is Horseshoe? The answer is given on the route page.
Approach 2: Lower Horseshoe Basin
From the Cascade Pass Trailhead, hike 3.7 miles to the 5,400-ft pass and continue east down into Pelton Basin. From the pass, descend the trail 3 miles to a junction at 3,600 ft. Take the left fork which turns a corner and heads north into Lower Horseshoe Basin. In high run-off situations, like after rainfall, the last portion of trail can become a stream course that's not too easy to travel. But it's not impossible. The brush ends at approximately 4,400 ft. Now what? How does one get up the cliffs to the upper basin?
At far left (NW) is a feasible route. It's not as direct but it has the least steepness between ledges and ramps. I have no other information other than having viewed it from afar. Right up the middle where the major streamcourse plunges down is another possibility. You will still have to deal with cliffs but there may be less of them. Farther to the right near where a minor buttress forms right of a streamcourse there is a cable hanging down from the cliff. A route up to the right of this cable is feasible (that's teh way we went) but it involves some Class 4 climbing on loose dirt and rocks. Unpleasant but doable. Even farther right there are a series of left-trending ledges. The lowest of these leads to the hanging cable. The upper one has an exposed portion for its first half. It's second half involves some brush and a stream crossing. The upper one--even with the exposed section--is probably better than the cable route.
Either way on the right will involve some amount of vegetated Class 4 for 100-200 vertical feet. The terrain backs off but remains steep for a few hundred more feet. Also, the brush above the cliffs can be a hassle. The farther you gee the less the brush, or so it seemed. However, there are more cliffs over that way, so you don't want to go too far right.
Eventually, at about 6,000 ft, the brush ends and the basin opens up to grass, heather, and rocks. Camping in the basin can be hard to come by. However, there is ample camping atop the 6,900-ft rock promontory at the center of the basin.
From the rock promontory (if camped there), climb up and right on talus or heather to below the rock wall of Ripsaw Ridge to about 8,000 ft where the rock wall ends at an ice-filled depression. You are now near the foot of Horseshoe Peak. But which crag is Horseshoe? The answer is given on the route page.
The peak lies within North Cascades National Park. Permits are required to camp within various zones. Sahale Arm is a different zone to Horseshoe Basin. Permits can be picked up at the ranger station in Marblemount. Blue bags (for your poop) are the standard. Also, you'll need that pesky Trail Park Pass to park. Well, you can still park but you risk a ticket. The lot is heavily patrolled...both by rangers and by thieves.
When To Climb
A winter ascent is not impossible but late spring to early fall is the best time. Early season snow-cover may make the traverse over to the peak more pleasant. Later on, the snow is gone and talus dominates. If you abhor talus, suggest you go earlier than later.
Camping is available at 7,600 ft on Sahale Arm and at 6,900 ft on the rock promontory in the middle of Horseshoe Basin. Some form of campsite could also be fashioned in Lower Horseshoe Basin (c. 4,400 ft). All of these will require a permit. Permits can be picked up at the Marblemount Ranger Station.
You can go here for a report on conditions in the area. Also, this page will be useful.
The peak is just slight east of the crest. Sometimes thunderstorms east of the crest can be a problem.