About this permit
This is the wilderness permit for the Happy Isles trailhead when your trip stays inside the park. NPS rates its demand "Very High" and describes the trails into Little Yosemite Valley as the most difficult wilderness permits to get in Yosemite.
The daily quota is 25 people: 15 through the weekly lottery 24 weeks out and 10 released seven days in advance at 7 am Pacific. Nothing is reserved for walk-ups.
Two details define the permit. First, the campground is compulsory: you must spend the first night in the Little Yosemite Valley campground, and camping anywhere between Yosemite Valley and LYV is prohibited. Second, the trailhead is Half Dome eligible, so you can add Half Dome permits for some or all of your group when you collect the wilderness permit, for $10 per person, with no advance reservation. What it does not include is a way out of the park: NPS marks it "not eligible to exit Yosemite on the John Muir Trail."
The route
NPS puts it at 9.6 miles round trip with 2,150 feet of gain, which understates the first half: everything you climb, you climb in under four miles. From Happy Isles the trail splits above the Vernal Fall footbridge: the Mist Trail is the shortest and steepest way up, and the John Muir Trail is longer and lower angle. They rejoin above Nevada Fall.
Above Nevada Fall the noise stops and the trail flattens into Little Yosemite Valley. This is a required first night: NPS states that with a permit for Happy Isles to Little Yosemite Valley "you must camp in Little Yosemite Valley campground on the first night (and may camp there on subsequent nights)." There is no camping at all between Yosemite Valley and LYV. Communal food lockers, two communal fire rings just outside the campground, a composting toilet, and no potable water. The Merced is the source and it needs treating.
From camp the options are Half Dome up the subdome and cables, or east up the Merced toward Moraine Dome and Merced Lake. What this permit will not do is take you out of the park: NPS marks this trailhead "not eligible to exit Yosemite on the John Muir Trail." That is the Happy Isles to Past LYV permit, a different quota.
Why it matters
NPS calls Little Yosemite Valley "the most popular area in the Yosemite Wilderness, mainly because it provides easy access to Half Dome," and says the permits for the trails leading there are the hardest in the park to get. This is the trailhead that buys you a night at the LYV campground and the option to add a Half Dome permit at the counter: no March lottery, no second application, $10 a head when you pick up the permit.
The feeling
You climb out of the valley in the spray of two waterfalls and arrive somewhere that feels like it should not exist: a flat, sandy stretch of the Merced River with pines and a granite wall on every side. The campground is minimally developed, there are no check-in procedures, and everyone there is going up the cables in the morning. By 5 am headlamps start moving through the trees.
