Forbidden Peak/Northwest Face of North Ridge

Getting There

Drive to Marblemount on SR-20. Register at the Marblemount Ranger Station. Take the Cascade River Road (Forest Road 15) for 21.7 miles to the Boston Basin Trailhead, a pull out just before the Cascade Pass Trailhead.

Approach

The trail initially follows the old Diamond Mine Road bed for about 1 mile to where the trail leaves the road sharply right and steeply up. Follow trail to Boston Basin. Either camp high in Boston Basin, off the meadows and on rock or snow, at designated upper campsites (6,400 ft) or camp on the flat bench (7,500 ft) below Sharkfin Tower, beside the Quien Sabe Glacier. You can also bivouac on the snow when crossing over the northeast ridge (called the “North Ridge") at about (7,700 ft).

Ascent Route

From Boston Basin, ascend the moraine and move along west edge of the Quien Sabe Glacier to 7,500 ft. Climb to Sharkfin Col (7,720 ft), the low point on the ridge and left of Sharkfin Tower, via 10 feet of 5.7 rock climbing and 200 feet of Class 3 gully. Rappel 150 feet down a loose gully from the Col to the Boston Glacier. Descend in a northward traverse through crevasses to 7,000 ft, passing a rock buttress. Then traverse, ascending to the north end of the Boston Glacier and cross over the northeast ridge (called the “North Ridge") at ~7,700 ft. This might be a better place to bivouac.

Descend to the north arm of Forbidden Glacier, near the base of an ice face. A large crevasse can open at 7,600 ft, slowing progress. Climb 30 to 40+ degree snow and ice on the Northwest Face 900 feet to the crest of the North Ridge’s upper section, then climb on to the summit. The icy face is composed of two ice sections divided by a narrow rock band. The upper section ends at the cornice at mid-ridge (~8,375 ft). Once on the ridge the firm rock can be climbed on or near the crest to the summit.

Descent Route

 Forbidden Peak is tough to descend but the airy East Ridge and West Ridge are the best two choices. The West Ridge is preferred if it is not crowded with ascending parties. Selected Climbs in the Cascades, Vol 1 contains good information about descent choices.

TRIP PROFILE

EQUIPMENT

Standard alpine ice climbing gear.

NOTES

• This wonderful North Cascades ice climb has a remote feeling and a circuitous spectacular route, but is not a good choice for a first ice climb.
• Rapid efficient travel and equanimity with exposure are key.
• Consider impact in Boston Basin when choosing a campsite.
• Intermediate Mountaineering credit before July 1, Ice credit after July 1.
• The camp to summit time are largely dependent upon crevasse conditions.
• Permits are required for camping and can be difficult to obtain. Obtain permit at the ranger station in Marblemount.

• Suitable Activities: Climbing
• Climbing Category: Intermediate Alpine
• Seasons: July, August, September
• Weather: View weather forecast

• Difficulty: Intermediate Ice Climb
• Length: 7.0 None
• Elevation Gain: 6,200 ft
• High Point: 8,815 ft

• Land Manager: North Cascades National Park
• Parking Permit Required: None
• Recommended Party Size: 6
• Maximum Party Size: 6
• Maximum Route/Place Capacity: 12