Water, lots of water 64 fl. oz. bag
Extra water container - 32 fl. oz. filled with water
Water purifying filter or tablets. Tablets are much lighter.
A walking staff or walking sticks - takes the load off your knees
Moleskin for hotspots on your feet - apply before they become blisters
Simple First aid kit - you never know
Sunscreen - small container used before and during the hike
Insect repellent - small container
Proper hiking socks - don't use department store socks they'll cause blisters on long hikes
Hiking boots that have been broken in
A whistle - to summon help in emergencies
Watch - to make sure you get off the mountain on time
A _light_ camera
Hat
Hiking pants - don't wear jeans they'll soak through with your sweat and become even more stifling
Nuts 'n fruit to keep you fueled along the way. Some kind of protein too.
Bananas and other sources of potassium to help prevent and relieve muscle cramps. Eat them the night before you set out.
Extra socks in case you feel like hiking up both Falls and getting very wet
Small roll of toilet paper
Small plastic bag for garbage - to take what you brought in back with you
Plan - everyone is going to get up to the top and get back down at different times. Everyone learn the route. Set a time to turn around and get off the mountain and back to camp before it gets dark.
A backpack with a belly belt - helps distribute weight off your shoulders

And that's just the hike. I don't know anything about camping and will defer to those who know better.

I was just up on the dome friday, so:

You need to break this down into two questions, since you won't be camping on Half Dome itself.

So a lot of the items that alphax has listed are great, but fine to leave at your campsite when you head up to the dome.

For the dome itself, the most important things are, in my opinion:
• water – either one liter with the ability to refill from the last water source, or two liters if not. A hydration pack is ideal.
• sturdy but flexible shoes – they need to be flexible for the cable climb, so I wouldn't recommend hiking boot, but also need to provide support. Modern hiking shoes are great; a sturdy pair of running shoes would be adequate (although wouldn't be good for any long distance hiking with a pack).
• clothing that doesn't retain water (very little cotton, NO denim), but can shelter from wind and sun. Make sure your hat won't fly off in strong winds – you don't want to be distracted trying to keep your hat on.
• A neckerchief/bandanna for wiping sweat. Should be your only cotton.
• sunscreen, sunglasses.
• snacks to reward yourself up on the dome.
• A camera that won't dangle or distract – I had a new Canon that slipped into the pocket of my hiking shorts, a buddy had an add-on pocket on the shoulder strap of his hydration pack.
A crucial element is that you'll need to have both hands free – so make sure you have a backpack or equivalent. If you want to bring hiking poles or a walking stick, you'll need to figure out how to stow it (or stash it) for the last portion of the climb.

We saw far too many hiking up with nothing but a quart bottle of water in one hand. Not enough water, and too encumbering for the climb.

Ordinarily I wouldn't say this, but don't worry so much about the emergency gear. The hike from the valley floor to the top of Half Dome is so busy that if you have a problem, someone with vastly more experience and equipment than you will be by in a few minutes. Bandaids and aspirin are okay – a lightweight pack of Wet Wipes are great to have (but remember to pack them out as trash).

It sounds like you are doing a multiday trip, so presumably you will be camping in Little Yosemite Valley – you do have your backcountry permit already, don't you?

The valley floor (Yosemite Valley, not Little Yosemite Valley) is about 4000 ft. elevation; the top of Half Dome is about 8800 feet. The 4800 foot elevation gain is a lot more exhausting than the distance itself, so it is important to pace yourself. If you camp in Little Yosemite Valley, you'll roughly split the climb into two stages, since LYV is about 6100 feet up.

Last water on the climb to Half Dome is a trickle of a stream right now, so I wouldn't expect it to be running through the summer. If you expect to refill your water bottles, it's important to have some way of purifying the water, either with tablets or some modern gadget like the SteriPEN.

For camping in LYV, any source for backpacking advice is adequate. Again, you'll need some way of purifying your water, but there are toilets (solar composting, which aren't flush but a significant step up from portapotties) so you can skip the toilet paper.

A last recommendation: see if you can find combo insect repellent/sunscreen. The river provides plenty of mosquitoes, and the elevation leaves more bad UV in the sunlight. Using a combo makes sure you cover all exposed skin. But you might get stronger SPF stuff for you nose, and sunscreen lipgloss as well.

i am hoping to hike half dome with two friends sat. 6/23. maybe we'll see you:)

i do want to add that i hope you'll consider carrying your own first aid/basic supplies. as someone who always thinks ahead and does so, i am tired of being relied on to assist other hikers who haven't taken ressponsibility for their own well being & comfort.

also, bring a headlamp;)

alphax's list and Richard's responses are fantastic! I hiked HD last July, and I'm allllmost ready to think about doing it again. ;)

The only thing I'd add to the lists: a parka, rain slick or other tarp-type thing for the slog up Vernal Falls. However, I haven't been back to Yosemite this year, so I can't tell you exactly how misty the Mist Trail is this summer. Anyone?

One thing that saved us was a big bowl of victory jambalaya and a cold beer back at camp. Your mileage may vary.

One last thing: climb early in the day, especially if there's even the slightest hint of rain in the Valley. Good luck, and enjoy!

Possibly not the nicest thing to read about just before heading up, but if it makes people more cautious...

The LA Times has a brief report (www.latimes.com/news/local...840.story), the San Francisco Chronicle goes into more detail (www.sfgate.com/cgi-bin/article.cgi and the Chronicle's Outdoors writer discusses it in his blog (www.sfgate.com/cgi-bin/bl...reen/detail The National Park Service has a minimal news release (www.nps.gov/yose/parknew...all2007.htm).

[In unrelated backcountry news, a boy in Utah was killed in a bear attack (www.heraldextra.com/content/...225895/). Keep in mind *no one* has ever been killed by a bear in Yosemite, and it was the first in Utah in memory. Somewhere around thirteen people have been killed by bears in all of North America since 2000. The use of food lockers and bear cannisters makes this even less likely in Yosemite -- the news reports from Utah imply the campers had coolers in the campsite with them, although that wouldn't be considered unusual in most campgrounds.]