The route climbs the obvious northeast ridge up from the Valentine Lake basin to the summit of Peak 3592m.
Start of the route.
From the town of Mammoth Lakes:
Take Old Mammoth Road to Sherwin Creek Road 4S08. Follow Sherwin Creek Road until a marked right turn for the Sherwin Lakes trail head. Take the Sherwin Lakes trail almost all the way to Valentine Lake before turning southwest when most convenient towards the obvious base of the northeast ridge of Peak 3548m+. Approximate approach distance: ~5 miles.
At the base of the ridge, just about everything can be climbing in the low 5th class range. To keep it 4th class or lower, proceed along the west side of the ridge and take the most appealing line to the ridge proper.
4th class start.
Once the ridge is gaining, follow it to the summit. It is mostly 2nd and 3rd class with a few sections of 4th to spice things up along the way.
4th class section.
To descend either drop down the north slopes or the west slopes. If dropping down the west slopes, you will end at Lake Mary instead of the Sherwin Lakes trail head.
A good pair of approach shoes or boots will get you up the ridge just fine.