Trip Report: Commonwealth Basin

Commonwealth Basin is a snowshoe-worthy area just across Interstate 90 from the West Summit Snoqualmie ski area. To get there, park at the free ski area parking and walk the freeway underpass to the trailhead. Take the first right after the underpass onto a forest road leading up to the trailhead. This road is likely closed and covered in snow in the winter.

There are trails from here but with the area covered in snow, the summer trails are obscured and you are free to explore. That said, the popularity of the area leads to very obvious snowshoe tracks following the PCT trail and the Commonwealth Trail. We mostly followed the Commonwealth Trail, with a couple detours to explore side trails from there.

While spending time in the shaded woods in the snow was wonderful, we began to long for sunlight on our faces by lunchtime. With a short detour, we found a cozy spot.


Northwest forests in deep snow always look so beautiful.


We were treated to a few peak-a-boo views (pun intended).



We thought the snow looked like marshmallows on these two tree snags.


I included a screenshot of our route below. Note the portion where we walked to the right of the map. We realized we were in avalanche territory and decided to turn around. Thanks, Mountaineer’s training!

The other fork heading to the left on the map was us looking for a sunny spot for lunch. We did have to cross creeks several times. At one crossing, we weren’t sure if we were going to fall in the creek or not. Luckily the snow bridge we used held, but as the afternoon sun heated the basin, it was much smaller upon our return than on the walk out(!).


All in all a lovely short walk in snow-covered woods. I would love to come back to the basin to further explore. It looks like you can access several peaks from here for both hiking and scrambling. I’ve been to Kendall Katwalk and a bit further on the PCT trail there but have not completed any other hikes in this basin (yet).

More information on Commonwealth Basin on the WTA website: