The 4,167-foot-tall Mt. Si is a classic area hike, running about eight miles round-trip. The 3,100-foot elevation gain makes the trail a popular off-season training-ground for locals, so don’t come here expecting solitude. On a clear day, the views at the summit can be worth the considerable physical effort.
To reach the trailhead, turn left on 432nd SE (Mt. Si Road) about a mile from the east edge of North Bend [1]. After you cross the Middle Fork of the Snoqualmie River, go right at the first intersection, then drive 2.5 miles to the parking lot, trailhead, and picnic area. The trail is generally snow-free April to November.
An easier alternative to Mt. Si is Little Si, offering views across Snoqualmie Valley. The trail is 2.5 miles each way and offers a still-considerable 1,574-foot gain. Get to the trailhead by following North Bend Way a half mile southeast from the Forest Service Ranger Station to Mt. Si Road; then turn left and go a half mile to a bridge. Park at the gravel lot here across the bridge, and walk downhill to the signed trailhead just past the fifth house on the right.
Links:
[1] http://www.moon.com/destinations/washington/south-cascades/snoqualmie-area/north-bend