Hiking to the top of Mt Tallac (2967m) takes about 3-4 hours. The altitude difference is about 1000m, the length is about 8 kms and the summit is at 3000m. The trail coasts four lakes. At the top, you get a very nice overview of Lake Tahoe on one side and some other lakes and what they call Desolation Wilderness. I suggest to leave one car at Mt Tallac trailhead, then park another car at the Velma Lakes trailhead (in Emerald Bay, farther north) and hike to "4 Q's Lakes". This is 15 kms. Then hike to Mt Tallac trailhead via Mosquito Pass, Aloha Lake, Gilmore Lake and Mt Tallac: 23 kms.