Mount Si Main Trail

A moderate/strenuous 8-mile round trip day hike with 3,200 feet of elevation gain. This is a popular trail in the foothills that offers a good workout and views of Puget Sound and the Upper Snoqualmie Valley.

Getting there

Take Exit 32 off of I-90 and turn left (north) onto 436th Ave SE. Drive 0.5 mile  and turn left (west) onto North Bend Way nd in 0.25 mile, turn right (north) onto Mount Si Road. Continue 2.5 miles and turn left into the large trailhead parking lot (600 ft).

on the trail

Mount Si (3,900 ft)

A moderately strenuous 8-mile round trip hike with 3,159 feet of elevation gain

The Mount Si "main" Trail begins at the far corner of the parking lot where just past the picnic area and outhouse. The trail is moderate for the first two miles and then steepens with more switchbacks until it ends in the meadow at the top.

The "haystack" jutting out of the meadow is the true summit and it can be scrambled. The route is challenging and exposed, and it' easy to send rock fall to unsuspecting hikers below, so this is not recommended.

The Talus Loop Trail makes an excursion off the main Mount Si Trail, reconnecting at Snag Flats.  It's 1.3 mi instead of the 1.0 mi if you were to stay on the Mount Si Main Trail.

"Si, Si Again" or "Double Si" Conditioner: Hike up the Mount Si Main Trail to the viewpoint near the summit, down the main trail, lunch in the parking lot, then a car shuttle to the Little Si Trail parking lot, up the Boulder Gardens/Old Si Trail to the viewpoint, down the  trail, car shuttle back to Little Si. Great for conditioning!  It's 16 miles and 6,400 feet of elevation gain.

scramble routes

blowdown mountain (4,560 ft) and crater lake mountain (4,351 ft)

a 12-mile round trip scramble with 4,400 feet of elevation gain, difficulty: strenuous 4, technical 2

From top of Mount Si continue on the path and road to where that road terminates northwest of Mount Teneriffe. Ascend past 4,440 ft, then follow the ridge northwest, descend west to a saddle, and then ascend continuing west to the summit of Blowdown Mountain. The views are not great, but in winter, this is all that daylight may allow. From Blowdown Mountain, travel north, descending to a saddle and then ascending to Crater Lake Mountain.

Dixie Peak (4,606 ft)

a scramble with 4,400 feet of elevation gain, difficulty: strenuous 4, technical 4

From top of Mount Si continue on the path and road to where that road terminates northwest of Mount Teneriffe. Ascend past 4,440 ft, then follow the ridge northwest and then north to Dixie Peak.

Information for LEADERS

scheduling & permits

If you are scheduling this as a non-course related activity, please limit your group size to 12 people. If you are scheduling a course field trip, please contact our Member Services Team to confirm the field trip and any permitting regulations.

  • Difficulty: Moderate/Strenuous
  • Length: 8.0 mi
  • Elevation Gain: 3,150 ft
  • 3,900 ft
Map
  • Green Trails Mt Si No. 174
  • USGS Mt Si
  • Green Trails Mount Si NRCA No. 206S
Activities

Upcoming Activities

There are no activities scheduled at this location.

Trip Reports
Titles

This is a list of titles that represent the variations of trips you can take at this route/place. This includes side trips, extensions and peak combinations. Not seeing a title that fits your trip? Log in and send us updates, images, or resources.

  • Mount Si via Talus Loop
  • Si, Si Again
  • Double Si
  • Blowdown Mountain
  • Crater Lake Mountain
  • Crater Lake & Blowdown Mountains
  • Dixie Peak
Resources

There are no resources for this route/place. Log in and send us updates, images, or resources.

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