Embark on a vertical adventure into the Cascades by climbing one of the most rigorous trails along Western Washington’s I-90 corridor. If you aren’t a fan of switchbacks this is the trail for you. With an elevation gain of 4,000 feet in only 2.5 miles, Mailbox Peak is notorious for a trail that essentially cuts straight up the mountain. At the very top of the mountain you can expect to be greeted by none other than a mailbox covered in signatures, filled with notes, books and comics. This physically demanding trail is frequently used as training for athletes, mountaineers and firemen. Ambitious hikers carry up trophies of their endurance to leave at the mountain’s summit for weeks or months at a time. You never really know what you’ll find at the top of the mountain. Believe it or not barbells, fire hydrants and even metal newsstands full of Seattle’s magazine The Stranger are not uncommon sights at the top of the trail. Avoid struggling up a snowy and dangerous mountain by heading to Mailbox Peak in the late spring and summer.

©Melissa Farage

From the parking lot walk around a blue gate and head up the gravel road. Approximately .5 miles later, you will find a small wooden kiosk on your left, providing information about the trail’s steepness, hazards and sign meanings. Read all of information carefully before embarking on your journey. Set off into the lush, mossy forest at the base of the mountain. Soon the trail begins to climb upwards out of the ferny, stream-fed glen. After a few switchbacks you will find yourself climbing upward through a tree-covered mountainside. The trail consists of short, nearly-vertical switchbacks up through the slender tree trunks and tufts of salal. The path climbs upward providing tree roots and rocks as stair steps as it quickly gains elevation.

©Melissa Farage

Continue along the trail. After nearly 1 mile the trail (believe it or not) gets steeper. Because this is not a well-maintained trail, there are many trail variations and shortcuts that hikers use to traverse the mountain. Always follow the white diamond-shaped markers to keep track of the true trail.
Roughly 700 feet from the top, the trees disperse to offer views of the surrounding Cascade Mountains. The lack of trees and rock falls offer scenic resting areas, but continue upwards for the true view. As you ascend above the trees, the slightly switch-backing trail becomes completely vertical, plunging upward towards the rocky mountain summit. As you finally reach the top of Mailbox Peak you will be rewarded by a 360-degree view of the Snoqualmie River Valley, Middle Fork Valley and South Fork Valley. Sign your name on the mailbox to leave your lasting legacy.


Length: 2.5 miles one way

Variety: out and back

Elevation Gain: 4,000 feet

Difficulty: Difficult

Season: Summer

Trail Open To: Hikers, Dogs

Passes/Permits: None

Facilities at Trailhead: None

Maps: Green Trails Bandera No. 206, No. 206S Mt Si NRCA, USGS: Chester Morse Lake


Driving Directions:

From I-90 East take exit 34 and head North. Turn right onto Middle Fork Road. Continue along Middle Fork Road until the pavement ends. The trailhead sign and parking are on the right, about 3 miles from I-90.

©Melissa Farage

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