ApproachThis route makes a nice loop if you want to see more country. It can be done in a long day from Tuolumne Meadows, or an easier outing if you are camped in the vicinity. You can loop north past Ireland Lake and the Voglesang HSC (longer, but mostly on trail) or south along Lewis Creek (shorter, and more isolated).
The route starts at Vogelsang Pass. To reach the pass from Tuolumne Meadows, start on the JMT and switch to the Rafferty Creek Trail. Follow this past the Vogelsang HSC (High Sierra Camp) to Vogelsang Pass - total distance about 9 miles.
Route DescriptionThe route from Vogelsang Pass to Parsons Peak is about two miles, and fairly easy. The steepest section is encountered as you leave the pass and head up the SW Ridge of the unnamed peak just south of Fletcher Peak. Bypass the upper portion of the unnamed peak on the southeast side and climb towards the ridge to the east.
The slope eases considerably here and the views are quite fine of the Yosemite High Country. Small bumps along the ridge can all be bypassed on the south side of the ridge, over easy class 1 ground. As you near the summit of Parsons along the NW Ridge, you will pass over the highpoint of Mariposa County. Congratulations, you are now a county highpointer, whether you care to be or not.
The USGS topo map indicates Parsons with a definitive summit, but you will be disappointed if you are looking for one. The summit is really a ridge running NW-SE over about 100yds distance. It is fairly impossible to discern which of several possibilities is the true highpoint.
You can return the way you came, or head SE from the summit if you are making a loop of it. You will soon reach the pass between Lewis Creek to the south and Ireland Lake to the north. The NE side of the pass is easiest, but the steeper SW side is only class 2, and only 600ft down to Lewis Creek - easier than it might look at first.