Half Dome
Credit: Paul Mckim

Learn how to prepare for a safe and enjoyable hike.

The hike to Yosemite’s Half Dome is one of the most beautiful and rewarding hikes in the United States, but it also one of the most strenuous. It is 15-17 miles round trip depending on your route and includes almost 5000 ft. of elevation gain. It culminates in a potentially dangerous ascent up a steep rock face using steel cables to hoist yourself up. If you are going to attempt this hike you need to be prepared. This article will tell you what you need to know in order to have a safe and enjoyable experience. 


In order to hike to the top of Half Dome you are required to obtain a permit from the National Park Service.  The permits only cost the nominal fee of $1.50 each. The permit system allows the Park Service to regulate the number of visitors to Half Dome; three hundred and fifty permits are made available for day hikers on each day.The upside to this policy is that you won’t find the top of Half Dome or the cables nearly as crowded as they were before the permit system was implemented. The downside is that it can be very hard to get a permit. When permits become available online they are typically snatched up in a matter of minutes.

If you want to be one of the lucky people who gets a permit you need to look at the Park Service website months in advance of your trip to find out when the permits will become available and then be prepared to act quickly when they go for sale online. The permits for each month are usually released 3 months before.  You are allowed to buy as many permits as you want, but can only reserve 4 per order so if you have a large group you may want to coordinate with other people to try to get as many permits as you can for a particular day when they become available. If you miss out on the initial rush for permits keep checking the website because people cancel and the park service also holds onto some permits and gradually releases them. Be aware that buying permits and selling them for a profit is unethical and against the law. 

Permits are only available for mid-summer and early fall, usually late June to sometime in October, depending on snow conditions. During the rest of the year the park service takes down the steel cables and you will be taking a high risk of death if you attempt to ascend half dome without the use of the cables. 


Afternoon thunder storms are fairly common during the summer in Yosemite, although there will be many beautiful days without them as well. Getting stuck in a thunderstorm on Half Dome is very dangerous and has resulted in deaths, both from lighting strikes and from people slipping on the cables. Check the weather reports before you go so you know what to expect. If you start your hike by 6 AM or earlier you will have a good chance of making the summit before any thunderstorms roll in in the afternoon, and you will probably make it back before dark. If you haven’t reached Half Dome and a thunderstorm arrives it is not safe to ascend and you must either turn back or attempt to wait out the storm in a safe location. 


It’s a good idea to carry at a water proof jacket or poncho because of the possibility of rain, and because the hike to Half Dome includes the Mist Trail, which is well, misty. Actually you hike right next to a large waterfall and if you go early in the summer you will get completely soaked from the spray. You don’t want to get stuck in the rain or on the Mist Trail in cotton clothing that will absorb water and make you cold and wet. 

It’s best to bring layers so you can deal with the changing temperatures throughout the day. The top of Half Dome and parts of the trail are completely exposed so if you are sensitive to the sun you will want a good sun hat that provides 360 degree protection for your face and neck (not just a baseball cap). And don’t forget the sunscreen! 


Bring one! A small and lightweight flashlight or headlamp could be a life saver if you end up getting back after dark. Even if you leave early and plan on being back before dark, you never know what might happen so be prepared.


Eat a good breakfast before you go, but expect to prepare it yourself because nothing is open in Yosemite Valley in the early morning.  Bring enough to tide you over until you can get back down to Yosemite Valley and eat a big dinner about 12 hours later. My favorite things to bring are beef jerky, nuts, and protein bars. A little dark chocolate is a nice boost during this long hike as well. 


You will need a lot of water for this trip. The only drinkable water that is provided on the trail is about 1 mile in at the Vernal Fall Foot Bridge so use that opportunity to top off your water bottles. Each person should plan on drinking in the ball park of 6-7 Liters of water on this trip. In order to avoid carrying all that water I suggest using a water filtration device such as the Katadyn Hiker Microfilter to safely refill your water bottles from the Merced River before it forks away from the trail in Little Yosemite Valley, which occurs about 5 miles in. 


Of course, you will need a comfortable backpack to carry all of your water, food, clothing and any other supplies you might want to bring such as a first aid kit. You don’t need a backpacking pack for this hike as it is only a day trip, but you do need a good size pack with around 25 liters of storage space or more. I recommend a hydration pack  with a hydration bladder system that holds 100 oz of water. 


Although I friend of mine managed to do this hike in tennis shoes when the weather was beautiful and the Mist Trail was dry, I would strongly discourage you from making that gamble. Tennis shoes don’t provide enough traction if you encounter slippery rocks and they usually provide no ankle support. Each year Search and Rescue volunteers end up responding to many of incidents of sprained ankles and twisted knees that could have been avoided by using better footwear. Also, you will need good traction on your shoes going up the steel cables. Get yourself a good pair of sturdy hiking boots before you go, and allow yourself plenty of time to break them in and make sure they fit right, otherwise you will be hurting on the trail. 

Be Prepared For A Long Haul

This is not an easy hike. Don’t attempt it unless you are reasonably physically fit. You don’t have to be in fantastic shape, but you should have decent stamina and no major leg injuries that could easily get aggravated by the repetitive strain of walking 15-17 miles.The famous steel cables are the most physically demanding aspect of the trip, although also the most fun for some people.  You will need some gloves to protect your hands going up the cables. There is a huge pile of discarded gloves left at the base of the cables, but I prefer to bring my own work gloves for this. 

Have Fun!

Don’t let my words of caution scare you. Thousands of people successfully do this hike every year and I can tell it is one of the best experiences anyone can have. On the way up you will be surrounded by magnificent forest and stunning rock formations as you travel alongside the beautiful Merced River, passing by two of Yosemite’s largest waterfalls. On top of Half Dome you will experience a phenomenal 360 degree view of Yosemite, including a direct view down to Yosemite Valley. Take your time to breathe in the fresh mountain air and soak up some of the most beautiful scenery in the world before you come back down.