Half Dome via Sub Dome
What to Expect
Safety Advisory
The cable section is genuinely dangerous when wet — granite becomes frictionless, and multiple fatalities have occurred from falls. If rain is even a possibility, turn around at Sub Dome. No view is worth your life.
Altitude sickness is real here. You're starting at 4,000 feet and topping out near 8,800, and the relentless climbing can trigger nausea and dizziness even in fit hikers. If you drove up from sea level the day before, your body hasn't adjusted.
Carry at least three liters of water per person. The Merced River crossings early on are your last reliable water sources, and the exposed granite on Sub Dome radiates heat like an oven on summer afternoons.
Trail Details
Pro Tips
Apply for your cables permit through the daily lottery at recreation.gov — only 300 hikers per day are allowed up, and walk-up permits the day before have roughly a 50% success rate on weekdays. Apply two days before your target date.
Stash a pair of grippy leather work gloves in your pack for the cable section — the metal cables shred bare hands and the smooth granite gets slippery with sweat. Dollar-store garden gloves work in a pinch but wear through fast.
Start before dawn to reach the cables by mid-morning. Afternoon thunderstorms roll in fast during summer, and the last place you want to be holding a steel cable is during lightning. Bonus: the early start means fewer people on the cables, which matters when you're clipped to the same line as 50 strangers.
Photos
NPS
