We wanted to hike a total of 30 to 40 miles in 5 days and we wanted to see the backcountry of Sequoia and Kings Canyon national parks (SEKI), specifically the majestic alpine zone around the treeline. Approaching that part of SEKI from the western slope would require dozens of miles of hiking. We needed to start and end from the east side of the Sierra where the roads get within miles of the summit, the start of the alpine zone. This narrowed our trailheads down to four: Onion Valley, Shepards Pass, Whitney Portal, and Horseshoe Meadows.
Of those trailheads, Onion Valley is by far the shortest distance to the SEKI backcountry at only four miles on foot. I didn't want an out and back hike, so I tried to put together a loop that connected trails starting and ending in Onion Valley. Here's what I proposed:
But my loop got vetoed because @xelanil pointed out that one of the trails goes over Harrison Pass. Which, as others have reported, is really really gnarly and a dangerous "trail". These are photos from Maia who posted them in the link above (https://plutoniclove.com/about/):
The trail density of the region is so low that it's nearly impossible to create a loop of trails without hiking less than ~75 miles or going off trail. We ended up settling for a route that started in Onion Valley and ended in Lone Pine Creek Canyon (Whitney Portal). It followed the summit of the Sierra via the John Muir Trail. Here's the route in Google Earth: