Distance: 1.2 miles (2 km) round trip
Elevation at trailhead: 4,000 feet (1,200 meters)
Elevation Gain: 200 feet (60 meters), more or less
Map Notes: The big green hikers mark the official trailhead, and the red line shows the brief route of the main trail. The yellow line is the longer alternate route that starts from the El Capitan Vista area. It takes you over a pretty stone bridge and is the preferred trail of hikers who like this paragraph.
The dark pink balloon marks a Southside Drive viewpoint that's worth checking out. To get here, just drive a few hundred meters east from the Bridalveil Fall parking lot to the El Capitan Vista area, pull over, and wander around until you find a view you like.
The green balloon marks the Northside Drive viewpoint. To get here, you'll have to drive east from Bridalveil and eventually loop anticlockwise.
The red balloon marks the Gates of the Valley. You can't turn left onto Southside Drive from Bridalveil Fall to get there - it's a one-way road. Instead, you'll have to drive east a few miles before you can loop around and head back west again.
The yellow balloon, which you'll have to scroll west to see, is the Tunnel View. This one is easy to reach from Bridalveil Fall - just turn left out of the parking lot and drive a mile or so.
More About the Traffic: Most of the roads in the western end of Yosemite Valley are on a one-way, anticlockwise loop. Highway 41 west of Bridalveil Fall is a two-way road (it's leaving the valley here), and Highway 140 west of the Northside Drive/Southside Drive intersection is also two-way (this road leaves the valley to points west and north), but the other roads in your view here are one way. So if you're in the eastern part of the valley and you want to get to Bridalveil Fall, you'll have to drive west to Pohono Bridge (the aforementioned Northside/Southside intersection), then loop back to the east again to reach Bridalveil. If you're at Bridalveil and you want to get to the Gates of the Valley (the red balloon), you'll have to go east on Southside Drive until the road loops around to the north.
Of course, if you're visiting Yosemite in the winter, you can probably ignore the entire preceding paragraph. Winter is construction-detour time in Yosemite Valley, when traffic gets rerouted in impressively imaginative ways, and you'll find yourself being directed to drive in lanes and directions that would assuredly land you in Yosemite Traffic Court if you tried them in the summer. Just stay alert and and be prepared to abandon virtually anything you learned in Driver's Ed at a moment's notice if someone in an orange vest requires it.