This is the shortest route to the summit. It can be done car-to-car in one day but good camping is available for those wishing to spend the night in a lovely sub-alpine setting.
There are no glaciers and hardly any cliffs to contend with if coming from the west. Instead, lower slopes are meadows—meadows which offer fantastic flowers in the height of summer and then huckleberries and rufescent scenes by late summer.
Overall, the route makes a counterclockwise hooking pattern to the summit.
Drive U.S. Highway 2 (Stevens Pass Highway) either 5.2 miles west of Coles Corner or approx. 6.1 miles east of Stevens Pass. On the south side of the highway is the turn-off for White Pine Creek Road. This is a fairly obscure turn-off so look sharp for it. There is a brown sign with the road name.
Take the White Pine Creek Road back west under the power lines. In 2 miles the road crosses Nason Creek in a canyon under a railroad bridge. Continue to road's-end (c. 2,800 ft) in about 4.9 miles from the highway.
Hike the mostly flat White Pine Creek Trail southwest for 2.5 miles, gaining 450 feet, to the marked junction with the Wildhorse Creek Trail on the left. Take the Wildhorse trail southward for 3.5 miles or so depending on where you want to leave it for higher ground under Big Chiwaukum.
It is possible to accidentally leave the trail too early. If in your eastward travels cross-country you come to be in a basin with a cliff on its south side at 5,800 ft, you are probably in the valley to Big Chiwaukum’s northwest.
You want to leave the trail at around 5,300 ft after a slight descent or possibly a little earlier at 5,400 ft after the trail climbs up in some switchbacks.
Alternately, you can continue south up the trail past the next low ridge. After crossing this ridge (about 4 miles from the aforementioned trail junction) you can leave the trail and bear ESE to Grace Lake (6,242 ft). There will be some 200-400 feet of steeper terrain on approach to the lake but it should be manageable. This lake would offer idyllic camping.
The upper west ramparts of Big Chiwaukum are a steep assortment of minor ribs and gullies that look most unpleasant. These can all be avoided by keeping right to climb the mountain’s southwest side.
If you leave the trail after 3.5 miles, bear southeast into the basin west of the summit. You should spot a 6,640-ft saddle on the western spur coming off the south ridge. This saddle is distinguished by talus below its north side. You can climb the talus up to this saddle or keep left of the spur ridge and scramble through a mild gully to cut-off some distance. If you go to the saddle, the spur ridge continuance is Class 2 but mildly brushy with stunted pines.
The western spur sort of turns and then merges with the alternately rocky and grassy southwest slope of the mountain. Up above a small gendarme looks like it may stymie a direct ridge run. This is not the case but you will need to cross an exposed notch atop the gendarme then downclimb its north side on Class 3 blocks (more exposure to the east face). You can avoid this gendarme by taking to ugly ledges and rocks and dirty gullies below its west face.
Once past the gendarme, return to closely below the west side of the crest. Continue running the ridge to the false summit (no, it’s not the summit!). At the false summit the true summit tower should wow you with its steepness on both sides. It’s only 100 yards away now.
It is necessary to scramble down the west side of the false summit for maybe 100 vertical feet to take a ledge northward. Some Class 3 all-hands moves should be expected.
A narrow gully/notch should be encountered just before the final summit scramble. Getting through this notch may well be the crux of the climb (Class 3/3+). Scramble up the southwest end of the summit tower then complete the climb south of the summit on the crest.
5,400 ft (all told)
Ice axe (and possibly crampons) in early season.
If late summer, an appetite for huckleberries all over and thimbleberries lining the lower part of the Wildhorse Creek Trail.
Water filter or purification means in late summer.
A bike would be handy for the first 2.5 miles of trail (the White Pine Creek Trail portion).