This is the fourth highest mountain in California. None of the routes are easy - the easiest is class 4. The most popular routes are the U-Notch + Clyde variation, a 4/5th class route, and the 4th class route from the West (South). This is quite a popular mountain and the goal of many a Californian mountaineer.
Drive to Big Pine in Owens Valley and then drive to Glacier Lodge. Hike the North Fork of Big Pine Creek for approaches to North-East facing routes.
Alternatively, drive to Bishop and then to South Lake; hike over Bishop Pass and into Dusy Basin. Cross either Thunderbolt Pass or Knapsack Pass (both cross-country) into the Palisade Basin. This is the approach for South-West facing routes.
Overnight wilderness permits are required at all times, and both both Bishop Pass and the North Fork of Big Pine Creek have use quotas in effect from May 1 to November 1. Permits can be obtained from the ranger stations in Lee Vining, Bishop or Lone Pine. If under quotas, make reservations is advance. More information can be found at the Inyo National Forest Visitor Center.
May to October. Few winter climbs (none entered in the summit log for the winter of 2000-2001 for example).
Wilderness camping allowed with a permit.
See Stephen F. Porcella & Cameron M. Burns, Climbing California's Fourteeners.
Check www.395.com for current conditions, or call the Inyo National Forest Rangers at (760) 873-2400 for conditions. Daily report are available at the ranger station.
Another nice source for weather data is Howard Sheckter's webpage out of Mammoth Lakes.