The Four Mile Trail at Yosemite National Park, California is a strenuous 9.6-mile out-and-back trail that leads to Glacier Point and features the most stunning views of Yosemite Valley, Half Dome, and El Capitan.
This trail leads up to Glacier Point, which ascents about 3,300-feet in just under 5 miles, making it very strenuous even for some of the most experienced hikers.
The trail begins with a moderate ascent for the first 1.2-miles until the grade becomes more steep for the rest of the trek up to Glacier Point. About half-way up the trail, hikers will start to get glimpses of El Capitan and Half Dome as well.
Hiking to the top is not easy, but it's well worth the effort. Once at Glacier Point, you'll find even more people than you found on the trail, since vehicles can drive to Glacier Point as well. Regardless of how many people are at the top, it's still the best view of Yosemite Valley you can get.
On the hike back, it's well worth checking out Union Point, which sits about 700-feet below Glacier Point and lies about 3-miles into the hike. You cannot miss signs for Union Point.
This trail is by far the most strenuous trails in Yosemite Valley, so hikers should come prepared. Trekking poles will help reduce weight from your knees, bring plenty of water and sunscreen, and do not hike any further than your physical capabilities.
The park entrance fee is $20.
Hikers will find limited parking at the trailhead, but it is along the El Capitan shuttle route. The shuttle runs from June through October, 9am to 6pm - plan accordingly.
For more trip details check out this NorCal Hiker blog post.