Forbidden Peak Circumnavigation

Getting There

Drive I-5 to just north of Mount Vernon, then east on SR-20 (North Cascades Highway) to Marblemount. In Marblemount, turn right onto Cascade River Road. Drive ~20 miles to a large parking area on the right (2,100 ft). If the road is driveable, continue ~2 miles to the Boston Basin Trailhead (3,200 ft). Sometimes the road is gated at Mile 18, the national park boundary.

Ski Route

Suggested Itinerary

Day 1: The road is often snowed in at or before the Eldorado Peak Trailhead. If it is, walk and ski the road to the Boston Basin Trailhead. Ascend through the trees to Boston Basin. Camp 1 is traditionally located near the base of Shark Fin Ridge.
Day 2: Boot up Sharkfin Couloir  which may involve scrambling on chossy rock. Descend the back side onto the Boston Glacier, rappelling if needed. Skin up to Forbidden Couloir to access the Forbidden Glacier, descend to Moraine Lake, and climb towards the Inspiration Glacier. Camp 2 is typically located below Eldorado Peak.
Day 3: Ski out following the standard Eldorado Peak approach, first climbing Eldorado Peak if desired.

Notes

• Exact locations of camps and ski route vary based on snowpack and conditions.
• Be prepared to ski around seracs and rappel portions of the route, as parts of the route can melt out even in April.
• A 30 meter rope should be sufficient for rappels and glacier travel, but this will vary depending on conditions.
• Consider extending your trip and climbing some peaks along the Ice Cap Slam.
• As of Nov 2022, following the Inspiration Traverse out towards Thunder Creek is not recommended, because of the bridge washout and required car shuttle.

information for leaders

Courses, paid clinics, staff-led programs, and course field trips require a Commercial Use Authorization. The Park typically accepts applications for 2-year CUAs  through mid-March each year, and CUA's are activity-specific. Please contact info@mountaineers.org if you would like to apply for a CUA for a field trip or paid clinic for an activity we do not already have a CUA for. Please follow all Mountaineers group guidelines when leading trips or courses in North Cascades National Park. 

Notes:

• Leaders are responsible for securing backcountry permits or other required permits even if  we have a CUA.
• Leaders must have all relevant CUAs with them in paper or electronic copy to show Parks Staff as requested. 
• All Hiking course field trips or paid clinics must have a First aid and CPR certified leader. Current (non-expired) certificates must be uploaded to the park web portal by Mountaineers staff prior to the trip
• All mountaineering field trips or paid clinics must have a WFR-certified leader and a leader with documented climbing certifications (an AMGA certification OR Mountaineers climb leader with a recent resume of training and experience). Both qualifications must be uploaded to the park web portal by Mountaineers staff prior to the trip

View list of current North Cascades CUAs

• Suitable Activities: Backcountry Skiing, Climbing
• Seasons: March, April, May
• Weather: View weather forecast
• Avalanche Terrain Rating Complex View avalanche forecast.

• Difficulty: Intermediate Mountaineering Climb, M3G Expert Glacier Ski
• Length: 21.0 mi
• Elevation Gain: 21,000 ft

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