By the way, the area around Kennedy Meadows on the east side is in the Sequoia National Forest -- the National Park itself is on the west side, just east of Visalia and Fresno. That's the part with the Really Big Trees:


There is no boondocking in the national park, but there is boondocking in the national forest. The national forest extends from the west side of the Sierras all the way to the Owens Valley on the east side.
If you have a very small Class C or a truck camper, with no towed vehicle, you could camp at Mineral King. We have a trailer, and that area is off-limits to us. I have heard that it is great.