Distance: 5.8 miles (9.3 km) round trip
Trailhead Elevation: 7,900 feet (2,400 meters)
Harden Lake Elevation: 7,600 feet (2,315 meters)
Total Elevation Change: 300 feet (90 meters)
The red line is the main trail to Harden Lake. It's 2.9 miles (4.7 km) long.
The green line is the bonus hike that takes you to a clearing overlooking the Grand Canyon of the Tuolumne - or some of it, at any rate. It's roughly half a mile (0.8 km) long. Views here are generally across the canyon to the northwest. If the bottom of the canyon were visible from here (alas, it's not), you'd be able to see the uppermost portion of Hetch Hetch Reservoir.
The light blue line is an alternate trail that departs from the main trail (which is actually a road) and returns to it 0.6 miles (1 km) later.
The purple line is the road to the trailhead at White Wolf Lodge, beginning from Tioga Road.