Features: Lake — River/Creek — Views — Waterfall
This is an ideal trail for trail running, minus the scramble up Red Mountain (too steep). Plenty of the standard roots and rocks, with a relatively flat mid section along the creek. In theory you could loop back on the PCT and do PCT-CCT loop-repeats.
Starting at the Pacific Crest Trail trailhead, you'll walk a very short distance then take an unsigned left on the old Cascade Crest Trail. This turn is just past the horse / equestrian sign. Follow this trail up into the valley; don't miss the side trail to the left to reach a peaceful waterfall (listen for the water). You'll cross the creek a few times and eventually link up with the more established Commonwealth Creek Trail. There were several nice looking campsites along the creek section of trail.
Head up the trail and begin climbing up onto the flanks of Red Mountain. To the west, Snoqualmie Mountain will become visible.
You'll reach an intersection of a trail heading to the west; I'd recommend continuing north for 100 yards or so for a nice resting spot at Red Pond. Refill your water bottles here if you haven't, then backtrack to the aforementioned intersection. Keep heading west, and you'll hit a 40-60 degree incline up the mountain. It is sustained at this angle to the summit; it is steep and difficult, so make sure you're prepared. I'd definitely recommend hiking poles, but my hiking partner went without them. Also, I'd recommend climbing helmets to avoid any falling rocks. As a point of reference, I'd consider this steeper and harder than the push to the Mailbox Peak summit.
As an alternative to the scramble, you can continue on the Commonwealth Creek trail, roughly where the scramble begins, but continue heading north, instead of starting the scramble. This will lead up to a ridge above Red Pond called Red Pass.
Overall, I'd recommend a solid GPS, in addition to routefinding skills if you attempt this hike. There aren't many signs, so you need to recognize where you are in the landscape. That said, the trail is well maintained and makes for a fun journey.
Credit for the GPX file: summitpost.org/red-mountain…
Lots of brush near the start, but transitions to old growth pine forest after .5 miles or so. The meadows and rock slides near Red Pond are quite beautiful.