I would hit the Sierra before Desolation Wilderness. But some attractive alternatives are these:
Sawtooths of Idaho, no bear canisters required (and no bear issues), 12 person max group size, low crowds, you register on the trail on the way in, no other permit required, fires allowed at most lakes, great fishing, very scenic alpine trails and lakes. Link to trip report and pictures http://backpackingtechnology.com/backpacking-trips/sawtooth-8-day-backpack/
White Clouds of Idaho: no bear canisters required (and no bear issues), 12 person max group size, low crowds, you register on the trail on the way in, no other permit required, fires allowed at most lakes, great fishing, very scenic alpine trail and lakes. . Link to trip report and pictures
Titcombe Basin in Winds, Wyoming: no bear canisters required (and no bear issues), 12 person max group size, low crowds, you register on the trail on the way in, no other permit required, fires allowed at most lakes, great fishing, very scenic alpine trail and lakes. . Link to trip report and pictures
You can't beat the Sierra for scenery, but you can beat them for bear canisters, fire restrictions, permit requirements, and overcrowding. But the best week long trips in California I know of are these:
1. South Lake to Sawmill Pass:
Sat to Saddlerock Lake
Sun over Bishop Pass to Dusy Basin, climb Mt. Agassiz
Mon to Palisade Basin, over xc pass climb North Palisade
Tues to Palisade Lake, over xc pass climb Sucker Peak (Jepson)
Wed over Mather pass, climb Split Pk
Thurs to Twin lakes
Fri to Woods Lake climb Cedric Wright, Coliseum
Sat over Sawmill pass to Sawmill Meadow
Sun to cars and home.
2. Cottonwood pack station to Symmes Creek
Sat: depart Cottonwood roadhead and proceed up Cottonwood Creek past Golden Trout Camp to South Fork Lakes area for camp (5 miles).
Sun: Ascend basin to New Army Pass for commanding view of Kern Basin and Trench as well as the Owens alley and Sierra Crest. Descent into Rock Creek basin past Rock Creek Lake, down the canyon to the9600 ft elevation for camp (9.5 miles).
Mon: Ascend the north side of the canyon, cross Guyot Creek to the saddle below Mt. Guyot. Hike to Crabtree Meadow and up the creek to Crabtree lakes for camp (9 miles). Layover day here.
Wed: hike back down Crabtree Creek to the meadow and join John Muir Trail. Proceeding North to Wallace Creek and climb Wallace Creek valley to timberline campsite (9 miles) . Have layover day.
Fri: return to John Muir Trail and hike to Wright Creek hike up the creek to timberline for camp (6 miles).
Sat: cross country over the ridge dividing Wright and Tyndall Creeks until we meet the Shepard Pass Trail. Then proceed over Shepard Pass and descend to Anvil Camp (5 miles.
Sun: Descend the eastern Sierra escarpment to the Symmes Creek roadhead. (7 miles) .
3. Toulumne Meadows to Devils Postpile
S Hike from Toulumne mdw to Rafferty creek
S Rafferty Creek to below Lyell Creek
M Lyell Creek, over Donahue and Island Pass, to Thousand island Lake
T Layover Day
W Thousand Island Lake to below Lake Ediza
T layover day
F lake Ediza to Trinity Lakes
S to Devils Postpile, get food drop, hike 2 miles out of DP
4. Devils Postpile to Lake Sabrina (or North Lake)
S to Purple Lake
M over Silver Pass, to Quail Meadow
T to Lake Marie
W over Selmer Pass to Evolution Valley
T over #&%!$ for Brains Pass, to Midnight Lake
F to Lake Sabrina, (or via Piute Pass to North Lake)
5. South Lake to Onion Valley
S start at South Lake, hike to Saddlerock Lake
S To Barrett lakes
M layover, climbed Polomonium, Sill
T to Palisade Lake
W over Mather Pass to Lake Marjorie
T over Pinchot Pass to Rae lakes
F To Onion Valley, over Glen, Kearsarge
6. Onion Valley to Mt. Whitney, Whitney Portals
S to Flower Lake
S over Kearsearge Pass to Bubbs Creek
M over Forester Pss to Wright lakes
W another layover for Group A, to Wallace lakes for Group B
T To Hitchcock lake for Group A, layover at Wallace for Group B
F over Trail Crest to the Portal, to summit of Whitney
S out to trail head Group A, down to Whitney Portal Group B
7. High Sierra Trail to Little 5 Lakes
Wolverton Meadows to Mehrton Meadows
To trail camp, above Bearpaw Meadows, climb Alta Peak
Past Hamilton lake, over Kaweah Gap, to Big Arroya
Thru 9 lakes basin to Little 5 Laks
Thru big 5 lakes to Lost Canyon
Past Columbine lake, climb Sawtooth peak, to camp at Timber Gap Creek
Near Bearpaw Meadows
To cars at Wolverton Meadows