← all objectives

Forbidden Peak — West Ridge

North Cascades (Boston Basin), WA III 5.6 Alpine Trad Grade III · ~4-8 short pitches of mid-5th (much simul-climbable) · long full day or two-day trip from camp (12-15+ hr car-to-car for the fit) alpine trad Descent complexity + party-induced rockfall: the gullies/couloir are full of loose rock, and the down-ridge is too low-angle to fully rappel — a mix of ~5-6 fixed-anchor rappels, 4th-class downclimbing and simul-descending is the standard exit, which is where most epics happen.

🚐 Join the caravan

A Fifty Classic Climbs of North America line and the quintessential moderate Cascades alpine rock route — an aesthetic, exposed knife-edge granite ridge on an 8,815 ft glacial horn where snow, ice, solid rock and big alpine scenery all converge. The most coveted 5.6 in Washington.

🥾 Approach · descent · season

Approach: Boston Basin Trailhead off Cascade River Rd (FR 15), ~21.7 mi from Marblemount. Steep, brushy climber's trail (~2-3 hr) up into Boston Basin; ascending traverse across the basin and snowfields/glacier remnants below the south face, up a class-3 hogsback/rock spur toward the upper glacier, then up steepening snow to the base of the West Ridge Couloir. Climb (or, late season, the rock gullies beside) the couloir to the notch on the ridge crest where the technical climbing begins. Roughly <2-3 hr from camp to the notch.

⬇️ Descent: Reverse the route down the West Ridge: a combination of short-pitch downclimbing, simul-down-climbing, and roughly 5-6 single-rope rappels off fixed anchors where the terrain steepens, back to the notch. Then descend the couloir (downclimb steep snow, typically with one ~30 m rappel) onto the glacier, and reverse the approach. Note fixed rap anchors on the way up.

🗓️ Season: Mid-June through September. Best when the West Ridge Couloir still holds firm snow (June-July) for a clean approach; by August the couloir can melt out and force looser rock gullies. Stable high-pressure weather essential.

🎒 Gear & food

Rack: Single rack ~0.3-2in (to ~3in late season), a set of nuts, ~6 alpine draws and ~4 double-length slings; 60 m rope (or a 60 m twin folded in half works well). Add ice axe, crampons, and consider a picket for the couloir/snow approach.

✅ Before you leave the trailhead

Auto-built from this dossier — ticks save on this device.

⚠️ Hazards · fire · emergency

  • Descent complexity + party-induced rockfall: the gullies/couloir are full of loose rock, and the down-ridge is too low-angle to fully rappel — a mix of ~5-6 fixed-anchor rappels, 4th-class downclimbing and simul-descending is the standard exit, which is where most epics happen.

🌤️ Live conditions

🟢 Send window: Fri
Fri
🌤️
38° 23°
Sat
☁️
43° 32°
💨22
Sun
☁️
61° 35°
Mon
☁️
57° 36°
Tue
🌦️
49° 30°

Auto-updated 20h ago · °F · tap a link for the mountain-specific picture ↓

💬 Comments

Comments are reviewed before they show up.