Boulder Garden Loop

The Boulder Garden Loop offers an opportunity to explore stone giants on a relatively untraveled path, despite its proximity to two of the busiest hiking thoroughfares in the Snoqualmie Pass region. It also is the access route to the Old Mount Si trail, for those who desire a less peopled approach to the Puget Sound region's most well-known hike.

The trail is a 1.5-mile, well-maintained loop through the forests to the South of Little Si. It starts off gently but later doles out a respectable grade, a hint of what is to come if the hiker opts to pursue the Old Mount Si trail. Its name comes from the moss-adorned granite formations, some of which are several stories tall, that appear to erupt from the forest floor on either side of the trail is it winds its way back to the more direct Little Si trail. For those ascending either the Little Si or the Old Mount Si trails, the Boulder Garden Loop provides some of the more interesting interior scenery along the way.

It is important to note that the Boulder Garden Loop is the access point for the Old Mount Si trail. Approximately one mile into the trail, there is a sign "Boulder Garden Loop Trail" with white arrows pointing to the left and right; look for a trail that takes off upward and to the right--that trail will take you to the Haystack.

Boulder Garden Loop

Map & Directions

Getting There

Driving Directions

Drive east on I-90 to exit 32 (436th Avenue SE). Turn left (north) over the freeway and drive 0.5 mile to North Bend Way. Turn left (west), and in 0.25 mile turn right (north) on Mount Si Road. Shortly after crossing the bridge, the road banks right. Just after this curve, look for a paved parking area on the left side of the road (if you get to the intersection with 444th Avenue SE, you've gone too far).

Take Transit

Take the bus to the trailhead!

Trailhead Direct will be running buses from Seattle to this trailhead in 2022. Stay tuned!