Ah, le creme de le creme of where the Snoqualmie Valley splits the Cascade Mountains - Mount Si. Unfortunately, I chose a cloudy day to climb this.
Take Exit 32 off I-90, go north, and hang a left on North Bend Way. About a half a mile you will run into Mount Si Blvd - hang a right and you are on your way. In a couple miles you will spot the trailhead, probably the biggest one in Snoqualmie Valley. On any given day you will encounter countless hikers, if you can find parking at all.
From the trailhead you will have a four mile, 3000 foot elevation gain to the top side of Mount Si. Not a lot of views on the way up - the views are left to those that make the peak. Not that I got to see any on the day I went (the 4th of July), hence no pictures.
The trail is well groomed, always a steady elevation gain, and finishes rather quickly (just four miles long). At the top, there are plenty of rocks for exploring and obtaining unique and great views of Rainier, Seattle, the Olympics, and the Snoqualmie Valley. Those more adventurous can climb "the haystack" - that pointy thing-a-ma-jig that you see from below that makes Mount Si distinguishable from other Cascade Mountains. It's another 250 feet up that, with no trail. Warning signs greet you. I chose not to give it a try, instead I am going to wait until there are views worthy of the ascent. Surely an incentive to come back!
The trail is kid friendly if the kids have the endurance - no crazy rock climbs, stream crossings, etc.