Although there are tons of hikers who make their way to the top of this trail, poor weather conditions nearly always lead to lost lives. The hike takes you up along Vernal Falls, and can afford you stunning sights like the rainbow that can be seen in this video!
While the hike to Vernal Falls is only 3 miles round trip, you can continue to Nevada Falls for a 7 mile round trip trek. And the end of this trail is not to be missed. You will get the most beautiful view of Nevada Falls, Liberty Cap, and the back of Half Dome, seen above!
So how hard is it?
If you're going to go past Vernal Falls, expect some difficulty. The stretches beside both Vernal and Nevada falls are quite steep. The last 100 meters or so are cut into the cliffside at Vernal falls.
If this kind of workout isn't for you, just proceed as far as the bridge looking upstream to Vernal Fall without exerting yourself quite so much.
Not only that, but this aptly named Mist Trail WILL get you wet!! In the spring, when the waters are at their strongest, you will get wet. Very wet. Taking-a-shower wet. Jumping-in-the-ocean wet. Bring rain gear. Seriously!!!
The real "danger" of this trail is that more people die here than anywhere else in Yosemite, as you can read about in this grim book. But why? It's not just because the stairs are slick when they get wet, no. It's that the river is much, much more dangerous than it looks. Hikers sometimes slip in the river, and are sucked under by strong currents that they cannot escape.
Also note that while water is available at the footbridge at the bottom of Vernal Falls, you'll need at least 1L of water to make it there! The Mist Trail starts at Happy Isles trailhead (YARTS shuttle stop #16, and within walking distance of Curry Village).