Monument Peak & Lake Mountain

A rugged, solitary trip deep in the Pasayten Wilderness to scramble two of Washington's 100 highest peaks. It's also known as the Monumental Slam.

Getting There

Drive SR 20 east 1.5 miles past Early Winters campground.  Turn left and drive 0.4 miles to Mazama.  Turn left on Harts Pass Road (No. 9140), which turns into Forest Road 5400. Continue 7 miles to the Lost Creek/Monument Creek trailhead (2,400 ft), an alternate approach, or continue on the the Buckskin Ridge Trailhead (6,900 ft) just beyond Hart's Pass.

approach & ascent

From Buckskin Ridge Trailhead, hike north on Trail No. 498, decsending to a junction in 1.3 mi. Take the right fork and continue down and cross the Middle Fork Pasayten River.  Hike another 0.25 mile to the junction with Robinson Creek trail and stay left heading north on Trail No. 478. After hiking 0.5 mile, locate the Ferguson Lake Trail (No. 474A) on your right and follow it 3 miles to a lake.  Note that this trail may not be marked or maintained. From the lake head southeast to the top of a cirque and cross to basin northeast of Wildcat Mountain then head to ridge between Points 7470 and 6645.  From here bushwhack down to Eureka Creek and make camp near the south fork. This point it is  10 miles and 2,400 feet of elevation gain.

From camp, cross Eureka creek and travel up east to 6,400 ft on the southeast ridge of Monument Peak.  Head northwest on the ridge for more than a mile.  Gain the Monument Peak summit (8,592 ft) via a short, steep scramble.

To climb Lake Mountain return down the ridge between Monument Peak and Lake Mountain, scramble east across the basin to the northwest ridge, then turn southeast to reach the summit of Lake Mountain.  Return to camp for a total of 8 miles and 5,800 feet of elevation gain.


  • Guidebook Reference: Summit Routes: Washington's Highest Peaks by Scott Stephenson and Brian Bongiovanni (Alpenbooks Press 2004).
  • There is an alternate approach from the Lost Creek/Monument Creek Trailhead, but it's slowly being reclaimed by nature.
  • Suitable Activities: Scrambling
  • Seasons: July, August, September, October, November
  • Weather: View weather forecast
  • Difficulty: Strenuous 5, Technical 3
  • Length: 26.0 mi
  • Elevation Gain: 10,600 ft
  • 8,597 ft
  • USGS Mt Lago
  • Green Trails Pasayten Peak No. 18
  • Green Trails Mazama No. 51
  • Green Trails Washington Pass No. 50
  • Green Trails Billy Goat Mountain No. 19
  • Trails Illustrated North Cascades National Park
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  • Monumental Slam

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