The trailhead for latter is located before the Lake Sabrina dam on the left-hand side of the road. There are very few parking spots and overnight parking is not allowed. There is free parking on the road near the campground (about 1km before the dam).

Lake Sabrina is located at the end of 168, west of Bishop, about 1.5 hours driving time south of Mono Lake, i.e. 6/7 hours from the Bay Area. From Bishop, take 168 west, aka West Line St, all the way to the end.

From Lake Sabrina (2780m) the trail climbs to Blue Lake. After Blue Lake take the right turn to Dingleberry Lake. After this lake, one has a choice. One can go left to Hungry Packer Lake, or right to Midnight Lake (3300m). Mt Darwin's northeastern ridge requires climbing skills. Mt Darwin's south-eastern approach is much easier and also represents a sort of "pass" to enter the Evolution region. This approach is via the cirque between Mt Darwin (easily recognizable because its top looks flat with two horns and is already visible from Lake Sabrina) and Mt Haeckel (even easier to recognize because it looks really steep, like a gothic spire). Getting there is not terribly easy. Hungry Packer Lake is locked by a huge waterfall. The only way to bypass it is to climb the ridge to the right (north). I had to get almost to the top before i found ledges that would take me to the other side of the waterfall. Alternatively, one can go to Midnight Lake and climb a chute on the left (south) of the lake that comes down from the same ridge. Once at the top of that chute one can follow the ridge to where it stops being a ridge (which turns out to be the other side of the waterfall).

From this point (whether you came from Midnight Lake or Hungry Packer Lake) it is just a matter of climbing one ridge after the other and coasting a series of lakes. Eventually the wall connecting Haeckel and Darwin becomes very visible. There is one last lake (3762m). Coast the lake to the right and head for the easily climbable part of the wall, near Darwin. At the top of this wall you have a view of the other side: Mt Spencer, the lake northwest of Mt Spencer, Evolution Lake in the distance, and, very near, the southwestern ridge of Mt Darwin. Walk over boulders to that ridge and follow it as it bends north.

My 2007 time:

• Lake Sabrina (2780m):
• Northern tip of Sabrina and beginning of the switchbacks: 30'
• Creek crossing and Blue Lake: 1h 30'
• Dingleberry lake and long creek crossing (3200m): 2h
• Fork to Midnight Lake and Hungry Packer lake: 2h 30'
• Hungry Packer lake (3370m): 3h
• Last lake (3762m): 5h 20'
• "Pass" (3962m): 6h
• Summit (4215m): 7h
• Midnight lake (3350m): 9h 30'
• Dingleberry lake and long creek crossing (3200m): 10h
• Blue Lake: 10h 30'
• Lake Sabrina: 12h

One can also descend to Spencer Lake (3500m), staying above this lake to the north (right), and then to Evolution Lake (3300m) which is along the John Muir Trail. From the southern end of Evolution Lake one can head for the west face of Darwinvia the rightmost chute.

To return via Darwin Canyon, from Evolution Lake walk up the John Muir trail until it bends sharply south. At this point turn right into Darwin Canyon. Ascend Darwin Canyon in the general east direction, and cross over to the other side on the lowest pass (which is just south of the more famous Lamarck Col), leaving Mt Lamarck to the north (left). Follow the series of small lakes (the "Schobert Holes") to Lake Sabrina (2780m).

Note that a loop can be made from Lake Sabrina southwest along Bishop Creek through a series of lakes to Bottleneck Lake (3400m). Then bend west through the Schober Holes (another series of small lakes) and climb the ridge (3800m) to the north of the moraine. Continuing straight west one reaches Darwin Canyon and its four lakes. After the fourth one, turn south to hit the John Muir trail. Continue south on the John Muir trail to Evolution Lake. Looking east from the center of Evolution Lake one sees Mt Mendel (northeast), Mt Darwin (east) and Mt Spencer (south). Head for the valley between Spencer and Darwin, coasting Spencer's Lake to the left. Eventually climb on the other side and start descending towards Hungry Packer Lake or Midnight Lake, where the trail leads back to Lake Sabrina.