Day hikers should be properly equipped (sturdy shoes, raingear, a hat), even for this comparatively small hike, because the trail rises thousands of feet. Fortunately, a prudent walker can simply turn back if the going gets too difficult. The hike ceases to be wheelchair accessible at the Happy Isles, but there are bridges to the Isles themselves.
A trail which links to the High Sierra Loop of the John Muir Trail starts after crossing from the Happy Isles to the north side of Little Yosemite Valley, a spur of the main Yosemite valley, which lies in the shadow of the Liberty Cap dome. Depending on your conditioning, a bridge which re-crosses the river, the halfway point of a hike to the foot of Vernal fall, can be reached in 15 to 30 minutes; but people have spent their entire lives exploring this enormous park, so time is not of the essence on a walk from the Happy Isles.
At the foot of Vernal fall, the mist from the river blankets the trail, which was improved during the WPA projects of the 1930s; the trail itself is called the Mist Trail. Here is where the raingear becomes handy. The trail now crosses a sheer face which is made somewhat easier by a single guard rail. At the top of Vernal fall, the Merced river traverses a shelf of granite, and the hikers frequently sun themselves to dry off after the Mist Trail.
The Emerald Pool is named for the color of the river here.
Up the trail, Nevada Fall, a waterfall that is over twice the height of Vernal Fall awaits the hiker, although there is no cascade of mist over the trail at this waterfall.
Hikers are cautioned that they should register a plan with the rangers so that their safety can be monitored; in this day of cell phones, that advice may be antique, but a cell phone can always be lost or broken.
Above this altitude, on the trail, further east, you may find yourself sharing the trail with a horse and rider; etiquette and safety demand that you yield to the horse, because if you spook the horse, both horse and rider may be pitched down the mountainside.
A set of camps on the High Sierra Loop await: Vogelsang (Birdsong), Tuolumne, May Lake, Glen Aulin, and more.