Take either Hwy 180 east from Fresno, CA or Hwy 198 east from Visalia, CA into Kings Canyon and Sequoia National Parks. You will be required to pay an entrance fee.  Turn north off of the Generals Hwy (about 8 miles southeast of Grant Grove) onto the road to Big Meadows (FS14S11). Follow the signs to Buck Rock Lookout, approximately 5 miles .  Visit this Sequoia National Forest link for camping information in the Buck Rock area. 

Detail (Ignore the red shading on the map):