Hike Distance: 2.8 miles (4.5 km) round trip
Trailhead Elevation: 4,750 feet (1,450 meters)
Lookout Point Elevation: 5,280 feet (1,610 meters)
Elevation Gain: 500 feet (150 meters)
As mentioned on the hike's main page, the trail seems to veer off into the woods, but actually tracks close to the road for its first third or so, and at a couple places you'll round the corner to find the road almost directly below you.
The Hetch Hetchy Reservoir is about five miles northeast of Lookout Point; zoom out a few times and it should appear on the map.