For gung-ho day hikers who don't mind getting up at the crack of dawn (or even earlier!), the 14- to 16-mile round-trip ascent of Half Dome is an epic adventure. In fact, it's the most popular day hike in Yosemite (and that's why you must apply for a permit in advance). Good hiking boots and gloves, plenty of extra water and food, and being in tip-top shape are necessary, too. But all of the advance planning and effort is definitely worth it when you're finally standing atop the giant granite dome, soaking up the incredible panoramas of the Yosemite Valley. It's a once-in-a-lifetime experience.
The Half Dome Hike: What's It Really Like?
Taking average hikers about 10 to 12 hours to complete, the out-and-back trail to Half Dome starts from the Happy Isles in Yosemite Valley. You have a choice: follow the Mist Trail, which switchbacks more steeply up past Vernal and Nevada Falls, or follow a longer section of the John Muir Trail, which winds up out of the valley more gently. Whichever trail you choose, they intersect just above Nevada Fall, where you'll find the last bathroom along the Half Dome trail. By now you're halfway there.
After switchbacking up through the forest to the base of Half Dome, the trail starts climbing in earnest. Now on the granite dome itself, the trail steepens and the rock underfoot becomes slickly polished by thousands of hikers' feet. The final stretch to the actual summit involves literally hauling yourself up a series of bolted rope cables. You can only hike to the summit when the cables are in place, usually from Memorial Day (late May) through Columbus Day (early October), depending on the weather. The cables are only 400 feet long and placed at an angle of no more than 45 degrees, but you'll swear they feel almost vertical. Surprisingly, it's arm strength that will get you to the summit, not your leg muscles.
Getting Your Half Dome Permits
Because summiting Half Dome is such a popular experience, the national park has instituted a permit requirement for day hikers who want to climb the cables. Day-hike permits are required seven days a week when the cables are in place (outside of which you can't ascend Half Dome unless you're a rock climber).
The permits can be obtained in advance through a lottery, at recreation.gov between March 1 and March 31. Results are announced in mid-April. A small number of permits are available every day the cables are up, with a two day in advance daily lottery.
A total of 400 permits will be issued per day between Memorial Day and Columbus Day (300 day hikers and 100 backpackers).
Staying Safe on the Trail
Don't attempt this hike when thunderstorms are forecast, lightning flashes are in the sky, or recent rainfall has made the trail and cables too slick to navigate safely. Start as early in the day as possible to avoid crowds on the cables later. Stay on the inside of the cables, allowing faster, stronger climbers to pass if it's safe to do so. If you aren't sure you can make it to the summit, consider turning around at the base of the cables. Some people have accidentally fallen to their deaths from this trail, so safety should be the most important factor in your hike.
The most important thing you can do to stay safe on Half Dome is to be well-prepared. Park rangers recommend bringing at least four liters of water per person for this hike. There is no potable water along the Half Dome trail, although you can boil or otherwise filter or chemically purify the Merced River water, which is available up until the Little Yosemite Valley. Bring along plenty of food and snacks to give you enough energy to reach the summit.
Wearing shoes (ideally hiking boots) with good traction is essential, as is bringing leather gloves that will help you grip the cables better, especially when you're coming back down from the summit. If you're sweating, it's all too easy for the cables to slip through your hands. Do not leave your gloves behind at the base of Half Dome, as many hikers do. Why? It's very important to pack everything out than you bring in, including food, trash, recycling and toilet paper. Litter is a problem on this popular trail, especially food and other scented items that cause black bears to become habituated to human presence. Remember to never feed wildlife in the park.
Half Dome Hiking Facts
Half Dome Elevation: 8,842 feet (2,650 meters)
Total Elevation Gain: 4,800 feet (1,600 meters) from Yosemite Valley
Best Time to Hike: Early season when the waterfalls are at their fullest from snowmelt.
Worst Time to Hike: Any day with even the slightest potential of rain. The slick granite quickly becomes dangerous with even the slightest rain.
Drinking Water: Potable water is available .8 miles up the trail below Vernal Falls, and can also be found at Happy Isles and Curry Village (.75mi from trailhead).
Facilities: Bathrooms are available at Happy Isles, below Vernal Falls, and above Vernal Falls.