The Rae Lakes Loops is one of the most popular hikes in the southern Sierra.  It is about 41.4 miles, if starting at the more usual Roads End TH in Kings Canyon.  A longer (50 mile) option approaches from the east via Kearsarge Pass from the Onion Valley TH.

Marcia Rasmussen adds:

The High Sierra Trail runs 49 miles from Crescent Meadow in the Giant Forest area of Sequoia & Kings Canyon National Park to a trail junction with the John Muir Trail at Wallace Cree