To access the Commonwealth Basin Trail, begin your hike on the Pacific Crest Trail north from Snoqualmie Pass. In just over 2 miles you'll see the junction for Commonwealth Basin Trail #1033. Head left and enjoy the switchbacks, old-growth forest, and beauty that the Alpine Lakes Wilderness has to offer.
Venturing out of the old-growth forest, you will be rewarded with views of mountain peaks and open valleys. There is a moderate climb as you head toward the headwall of the basin that leads through a series of tight and steep switchbacks. After 4 miles the path levels out in a meadow of heather that is surrounded by open views. From the meadow's elevation of 4,860 feet you will have views of Red Pond. If you wish to venture to Red Pond, a little narrow walking path leads to its base. Depending on the season, you may find wildflowers and huckleberries above and below the pond, making this a lovely stop to enjoy while hiking to Commonwealth Basin and Red Mountain.
The last half mile of this trail climbs 500 feet up to the saddle of Red Pass, a fantastic lookout between Lundin Peak and Red Mountain. This final stretch creates a level of satisfaction and desire to explore the ridge and soak up the grand views. Once you venture back down, appreciate the views of Red Pond and the open space before finishing your hike back on the PCT.