Section 1. Happy Isles to Tuolumne-Mariposa County Line: Merced River (16.6 miles) From the Happy Isles shuttle bus stop, cross the river on the large bridge straight ahead and then turn right (south) to reach the true John Muir Trailhead, a large sign advertising distances to Half Dome, Tuolumne Meadows, and Mt. Whitney. Note that the JMT originally began at Le Conte Memorial, several miles farther west in Yosemite Valley. Today, few--if any--hikers begin with this extra distance, but you could take the shuttle bus to the Le Conte Memorial and then follow the trail that skirts the southern side of Yosemite Valley to reach Happy Isles. At its start, the asphalt-surfaced trail climbs steeply southward and upward on the east wall of the river canyon. You''ll have plenty of company from here to the junction with the trail to Half Dome.

The route curves around the base of Sierra Point, which was a popular vista point until a rockfall closed the trail many years ago. Continue eastward, high above the turbulent Merced River. You descend briefly to cross the river on a stout footbridge [4,400'' - 0.7/0.7], which offers a superb view of Vernal Fall; be sure to pull out your camera. Across the bridge are toilets and a drinking fountain that has spouts for both drinking and filling water bottles. This is the last treated water you will find before reaching Sunrise High Sierra Camp. A short distance above the bridge is a junction, where the Mist Trail continues straight ahead and the JMT turns south to begin switchbacking up the canyon''s steep south wall [4,530'' - 0.

2/0.9]. The Mist Trail skirts the southern edge of the river, following stairs up the steep river channel to the top of Vernal Fall. This scenic route is considerably shorter and steeper, and in spring and early summer, it is so wet from spray that you will be drenched once you reach the top. Nonetheless, if you are up for the challenge of hauling your pack up this route, it is well worth the views--and the hot sun will quickly dry your clothes. From the top of Vernal Fall, you could choose to climb up to Clark Point (which has stunning views to Nevada Fall) to rejoin the JMT sooner, or continue ascending the Mist Trail to the top of Nevada Fall. The two trails rejoin at the top of Nevada Fall. Assuming you continue up the JMT, you will shortly pass a signed horse trail coming in from the west and then begin ascending switchbacks.

The tree species on this slope are unique to this stretch of the JMT and disappear as you climb higher. Douglas fir is the main conifer species, while three broadleaf species are California black oak, identified by its large, lobed leaves; bigleaf maples; and California bay laurels, which have long, skinny, leathery, and highly aromatic leaves. Meanwhile, the ever-squawking Steller''s jays (dark blue birds with a black crest) will follow you several thousand feet higher. You will undoubtedly stop and watch these, as the switchbacks seem interminable and are tough on your feet, since many were once paved. The gully you are ascending is the only passable route up the headwall of cliffs. After the climb, you will enjoy a break at the Clark Point junction to take in the view of the waterfalls and the surrounding canyon [5,490'' - 0.9/1.9].

Continue upward on the JMT, first on switchbacks and then along a walled-in section of trail that clings to the cliff. By the end of summer, damp sections of this trail are colored by the bright red flowers of California fuchsias and the creamy white, five-petaled flowers called marsh grass of Parnassus. The view from the west end of the walled traverse is spectacular. In the distance is the rounded backside of Half Dome and, to the east, Nevada Fall dropping 594 feet. Mt. Broderick and Liberty Cap are the two prominent domes across the drainage--in front of Half Dome. While these domes were once glaciated, their rounded tops actually exist due to preexisting fractures in the rock. These fractures cause the surface layers of rock to peel off like the layers of an onion; the technical term for this is exfoliation.

At the end of the traverse, you pass a signed junction with the Panorama Trail [6,020'' - 1.0/2.8] and almost immediately a second junction. The trail bends to the northeast, leading to the top of Nevada Fall. A sturdy footbridge leads over the raging waters--after which the trail passes a spur to a fenced vista point, follows a line of rocks across slabs, and zigzags down to meet the upper end of the Mist Trail near some toilets [6,000'' - 0.4/3.3]. From here, you climb a short distance up sandy, rocky switchbacks, on which vegetation includes huckleberry oak; Fremont silktassel, with long, dangling tassels of flowers; black oak; and, occasionally, a towering Jeffrey pine, with long needles and large cones.

After a short climb, you drop into Little Yosemite Valley, your first flat section of trail, and traipse along the riverbank. In early summer, the western azaleas that line the river are thickly covered in aromatic white flowers. At a junction [6,110'' - 0.6/3.9], the JMT takes the right fork, while the left fork serves as a shortcut, and the two merge again a little north of the Little Yosemite Valley camping area. The JMT, mostly under dense forest, roughly parallels the now unseen river, which is separated by a crude log fence. In early season, you may see the peculiar red snowplant that is non-photosynthetic, instead obtaining energy from nearby tree roots. Soon, the JMT turns north (left), diverging from the trail up the Merced River, and reaches the large Little Yosemite Valley camping area, the first legal campsite since Yosemite Valley.

Here there are toilets and food-storage boxes. Soon after the toilets, your path re-intersects the shortcut trail [6,130'' - 0.6/4.5]. Stay to the right and resume climbing.