Four Mile Trail is a moderate to strenuous trail leading from Yosemite Valley to Glacier Point. The trail begins near the Swinging Bridge recreation area, and climbs 4.6 miles to Glacier Point.blank">http://www.nps.gov/yose/planyourvisit/valleyhikes.htm 4 Mile Trail was originally constructed in 1872 and was 4 miles in length. In the early 1900's the trail was reconstructed and lengthened to 4.6 miles, yet the original name has remained. The first half of the trail is full of grand views of _El Capitan and Yosemite Falls, as well as the Merced River as it runs through the valley. The second half of the trail provides several good views of Half Dome. There is no potable water along the trail.