This classic route crosses the High Sierra, from Road's End (near Cedar Grove) on the west side, to Onion Valley (above Independence) on the east side.
Starting in the depths of King's Canyon at 5000 feet, the route climbs the rugged Bubb's Creek Trail and a portion of the John Muir Trail, and culminates with the crossing of Kearsarge Pass (11,800 feet) before descending to the Onion Valley Trailhead (9200 feet).
Approximately 21.4 miles with 7600 feet of cumulative climbing. (Note that for an FKT it would make more sense to run it the other direction for the net downhill.)
One difficulty of doing this route is the massive car shuttle - around 365 miles and at least 6.5 hours by the quickest route. Hikers usually do his by going in 2 groups in opposite directions, and doing a key exchange.
Thanks much for including my little route so quickly. One minor correction, to the name of the route: Road's End is in Kings Canyon National Park, rather than Sequoia. So a more accurate name might be "Road's End in Kings Canyon - Onion Valley (CA)"