The standard scramble up Seven Fingered Jack's craggy summit towers, climbed from the same Leroy Basin camp used for neighboring Mount Maude and Mount Fernow.
Follow the shared Phelps Creek Trailhead approach: drive Forest Roads 62 and 6211 to the trailhead, then hike the Phelps Creek Trail roughly 3 miles to the Leroy Creek crossing and continue up the steep climbers' path into Leroy Basin (about 6,000-6,100 feet) for a high camp. From the basin, two parallel lines lead up toward the peak: a rock gully heading directly northeast, or a gentler ridge just to its right; both converge in a flat area around 6,800 feet where the broad southwest slope begins. An obvious snow couloir at this point offers an easier bypass of loose lower slopes early in the season and leads to a higher point on the southwest ridge; alternatively an easy ramp on climber's left reaches the same ridge. Once on the southwest ridge, ascend talus toward the leftmost (northernmost) point visible from the basin below; the true summit sits to the left of the visible spires or "fingers" that give the peak its name. Steep sections along the way can generally be passed on either side without real difficulty.
Many parties descend via scree slopes on climber's left of the ascent gully rather than reversing the same line, which is faster but still loose underfoot; either way this is a straightforward reversal in good visibility.