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).

PUBLIC TRANSPORTATION - TRAILHEAD DIRECT

On weekends and designated holidays, Trailhead Direct takes riders to three hiking destinations: Mount Si, Issaquah Alps, and Mailbox Peak. All buses are run by King County and regular fares apply, just like in the city. By establishing this service, Trailhead Direct aims to increase accessibility to local trails, limit vehicle congestion in trailhead parking lots, and reduce carbon emissions. If you will have a group of more than 10 people, please fill out this form to reserve seating.

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

  • Permits are required in this area for all fee-based (course-related) activities, regardless of group size, and all free activities involving 13 or more people. Leaders may list trips at this route/place with the understanding that they need to verify that a permit has been obtained before running the trip (if required as outlined above). Permit applications are submitted to WA Department of Natural Resources annually in December. Please contact Amanda Virbitsky at amandav@mountaineers.org with any additional questions, or to obtain a permit for the current calendar year.
  • Difficulty: Moderate/Strenuous
  • Length: 8.0 mi
  • Elevation Gain: 3,150 ft
  • 3,900 ft
Map
  • Green Trails Mount Si NRCA No. 206S
  • Green Trails Mt Si No. 174
  • USGS Mt Si
Activities

Upcoming Activities



Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, including skill practices conditioning trips
Difficulty: Moderate/Strenuous
Sun, Jan 20, 2019
No Prerequisites
3 participants 0 instructors
Registration closed Jan 18
Seattle Branch

Day Hike - Mount Si Main Trail

Day Hiking Trip
Foothills winter conditioner, open to all branches. Dog friendly :)
Difficulty: Moderate/Strenuous
Wed, Jan 23, 2019
No Prerequisites
5 participants 2 leaders
Canceled
Foothills Branch

Day Hike - Mount Si Main Trail

Day Hiking Trip
Foothills Conditioner, Open to All Branches
Difficulty: Moderate/Strenuous
Sat, Jan 26, 2019
No Prerequisites
6 participants
Registration closes Jan 24
Foothills Branch

Day Hike - Mount Si Main Trail

Day Hiking Trip
Foothills Conditioner, Open to All Branches
Difficulty: Moderate/Strenuous
Sun, Jan 27, 2019
No Prerequisites
7 participants
Registration closes Jan 25
Foothills Branch

Basic Climbing - Mt Si Conditioner Field Trip - Mount Si Main Trail

Climbing Field trip: Basic Climbing Course
Basic Climbing - Mt Si Conditioner FT
Difficulty: Moderate/Strenuous
Sat, Feb 2, 2019
Prerequisites
2 participants 0 instructors
Registration closes Jan 31
Everett Branch

Conditioning Hikes - Mount Si Main Trail

Day Hiking Field trip: Alpine Scrambling Course
Scramble conditioning hike
Difficulty: Moderate/Strenuous
Sat, Feb 16, 2019
Prerequisites
0 participants 0 instructors
Registration closes Feb 14
Seattle Branch

Conditioning Hikes - Mount Si Main Trail

Day Hiking Field trip: Alpine Scrambling Course
Scramble conditioning hike
Difficulty: Moderate/Strenuous
Wed, Mar 6, 2019
Prerequisites
8 participants
Registration closes Mar 4
Seattle Branch

Conditioning Hikes - Mount Si Main Trail

Day Hiking Field trip: Alpine Scrambling Course
Scramble conditioning hike
Difficulty: Moderate/Strenuous
Wed, Mar 13, 2019
Prerequisites
9 participants
Registration closes Mar 11
Seattle Branch

Intermediate Fitness Test - Mount Si Main Trail

Day Hiking Field trip: Intermediate Climbing Course
Mandatory fitness test for students in the Intermediate Package - Palushock Mentor Group
Difficulty: Moderate/Strenuous
Thu, Mar 14, 2019
No Prerequisites, Leader's Permission Required
0 participants
Registration closes Mar 8
Seattle Branch

Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, including skill practices conditioning trips
Difficulty: Moderate/Strenuous
Tue, Mar 19, 2019
No Prerequisites, Leader's Permission Required
5 participants 1 instructor
Registration closes Mar 17
Seattle Branch

Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, including skill practices conditioning trips
Difficulty: Moderate/Strenuous
Thu, Apr 4, 2019
No Prerequisites, Leader's Permission Required
10 participants 0 instructors
Registration closes Apr 2
Seattle Branch

Conditioning Hikes - Mount Si Main Trail

Day Hiking Field trip: Alpine Scrambling Course
Scramble conditioning hike
Difficulty: Moderate/Strenuous
Fri, Apr 5, 2019
Prerequisites
8 participants
Registration closes Mar 14
Seattle Branch

Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, including skill practices conditioning trips
Difficulty: Moderate/Strenuous
Sun, Apr 14, 2019
No Prerequisites
8 participants
Registration opens Apr 7
Seattle Branch

Conditioning Hikes - Mount Si Main Trail

Day Hiking Field trip: Alpine Scrambling Course
Scramble conditioning hike
Difficulty: Moderate/Strenuous
Tue, Apr 16, 2019
Prerequisites
10 participants
Registration closes Apr 14
Seattle Branch

Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, including skill practices conditioning trips
Difficulty: Moderate/Strenuous
Thu, May 2, 2019
No Prerequisites
9 participants
Registration opens May 7
Seattle Branch

Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, Lalonde SIG. Timed Conditioner with Weight
Difficulty: Moderate/Strenuous
Sun, May 5, 2019
No Prerequisites
3 participants 1 instructor
Registration closes May 2
Seattle Branch

Seattle SIG Practices and Conditioners - Mount Si Main Trail

Climbing Field trip: Basic Alpine Climbing Course
SIG activities, including skill practices conditioning trips
Difficulty: Moderate/Strenuous
Mon, May 13, 2019
No Prerequisites
9 participants
Registration opens May 14
Seattle Branch
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
  • 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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