Hard Mox, the southeast of the two Mox Peaks summits, is widely considered the single most difficult summit on the 100-peak Bulger List. It is climbed from the same Redoubt Glacier Saddle high camp as Easy Mox, via a long and convoluted ledge-and-gully system to the Ridge of Gendarmes, followed by a multi-pitch technical rock finish.
This route starts in Canada. From the border, take Trans-Canada Highway 1 to Exit 119A (Chilliwack/Sardis), head south through town for about 3.4 miles, then turn left onto Chilliwack River Road just before the river bridge. Follow Chilliwack River Road roughly 31.7 miles, paved for about the first 25 miles and rough washboard gravel for the remainder along Chilliwack Lake, to a point just before a yellow bridge over Depot Creek. Turn left onto the unmarked dirt Depot Creek Road roughly 200 yards before that bridge; the turnoff is easy to miss and there are several side spurs in the area, so route-finding here should be double-checked against a GPS track rather than signage alone. The road is high-clearance-4WD terrain and becomes increasingly rough and overgrown; a locked gate is sometimes present around the 0.9-mile mark, which would add roughly 1.5-2 additional miles and elevation gain on foot if closed. Where passable, vehicles have historically driven as far as about 2.5 miles from the Chilliwack River Road turnoff. Park at the road-end or the large open intersection near a broken bridge over Depot Creek, at approximately 2,350 ft. From the parking area, hike the old road bed roughly 2.5 miles to an old clearcut, then follow a way-trail about 200 yards into old-growth forest and across the international border. A small registration kiosk sits at the border swath, roughly 1.5 hours and 500 ft of gain above the cars. From the border, follow the climbers' path up the Depot Creek valley through old-growth forest for roughly 3 more miles. Near a large waterfall the route becomes wet and loud; a very wet, slippery rock step of roughly 8 ft must be climbed beside the falls. This point, the base of Depot Creek Falls (one of the tallest waterfalls in Washington, with a total drop of roughly 967 ft), is reached at roughly 4.5-5 hours and 1,600 ft of gain above the cars. Continue up a very steep way-trail alongside the falls, gaining roughly 1,000 ft on a mix of dirt tread and boulder field, until the valley opens into a flatter basin around 4,800-5,000 ft (roughly 7-7.5 hours and 2,650 ft above the cars). A forest-bench campsite here is a viable first-night stop for parties not pushing all the way to Ouzel Lake in one day. From the basin, a way-trail hugs the north edge of the valley across an outwash and boulder plain to small Ouzel Lake (approximately 5,700 ft), the standard base camp for this group of peaks. This point is typically reached in roughly 9-9.5 hours and 3,550 ft of gain from the cars. A precise trailhead-to-Ouzel-Lake mileage is not well established; based on typical travel times over this terrain, the one-way distance is roughly estimated at 8-10 miles. From Ouzel Lake, scramble up the broken, loose ledges and buttress above the lake to reach the Redoubt Glacier, then rope up for glacier travel. Cross the glacier heading southwest/west to the Redoubt Glacier Saddle (approximately 7,150-7,300 ft), the standard high camp for both Mox Peaks, typically 3-3.5 hours and 1,550 ft above Ouzel Lake. Visibility on the glacier can drop to as little as 50 yards in poor weather; navigation should rely on map and GPS rather than sight alone in those conditions. From the Redoubt Glacier Saddle, traverse roughly 2 miles across moderately steep snow slopes at the head of the Redoubt Creek basin, heading generally east toward the col separating the two Mox summits, known as the Col of the Wild. The final approximately 100 ft to the col crosses unstable talus over loose sand and can be slow going even though it is short. Reaching the Col of the Wild typically takes 1.5-2 hours and about 1,000-1,050 ft of gain above camp.
Descend the climbing route. Three single-rope rappels typically lead from the summit area down to the high notch below the summit tower, followed by further downclimbing and rappelling back through the gully system, over the Ridge of Gendarmes, and down to the Col of the Wild -- roughly 400 vertical feet of rappelling and downclimbing in the gully system alone. Even without incident, the full descent back to camp can take 9-10 hours; it should be treated as a full day in its own right rather than an afterthought to the climb.