From Highway US-395 in Bishop, drive approx. 10 miles north to the turn-off to Rovana. Drive west through Rovana and up Pine Creek Canyon to the Pine Creek trailhead. Hike up the trail to where the Italy Pass Trail goes north. Follow the Italy Pass Trail to a flat area of slabs and meadows just past Honeymoon Lake. Leave the trail and head west up to Royce Pass. From Royce Pass, hike west along the northern shore of Lake 11,725' to a point just past the central sand chute.
A good view of the peak, including the Royce Lakes and Royce Pass, can be seen here in this excellent photo by Craig Peer. Spire Peak is the peak directly above the foreground Royce Lake. Royce Pass is right of Spire, and Peak 12,563' is right of the pass.
From the bottom of the left side of the south face, scramble up clean, enjoyable granite steps (mostly class 3, some class 4) to a less-steep point on the southwest ridge. Cross over to the north side of the ridge and continue up class 3 ledges to an impasse, then cross back to the south side and traverse to the base of the class 4 summit blocks.
A good pair of boots are recommended. In early season an ice axe may be needed to cross a small snow patch below the southwest ridge.
If you have information about this route that doesn't pertain to any of the other sections, please add it here.