Take HWY 138 to Pearblossom. Turn south on Longview road. Turn east on East Avenue 'W' / Valyermo Rd. Follow Valyermo Rd for approximately 8 miles to Big Rock Creek Rd. Follow Big Rock Creek Rd to turn off for South Fork Campground, approximately 4 miles from Valyermo Rd. Day parking is off to the right, just before the entrance to the campground.
The trailhead is at the back of the campground in a group camp site. After crossing to the west side of the stream the trail makes its' only few switchbacks. The first 1 1/2 miles is steep and exposed so watch your step. It is an impressive canyon for the San Gabriels. You begin at an elevation of 4540', in desert brush and Yucca. The trail climbs quickly along the west side of the canyon through oak forest and then pine. At the end of this 5.2 mile trail you will reach Islip Saddle, where it meets the Pacific Crest Trail. The PCT climbs 1.6 miles to the top of the south ridge. Here the trail branches. To the west(left) the PCT descends to the Kratka Ridge Saddle, to the nort(right) is the trail leading to the summit.(8214') There are actually three summits and the registry can will be found in a pile of rocks on the middle summit.
In warmer months a good pair of hiking shoes or boots will do. Winter may require snoe shoes or crampons depending on the conditions.
Other trails from this campground lead to Devil's Punchbowl( 2.2 miles to the west) and Vincent Gap(5.3 miles to the east) Devil's Punchbowl is of course famous for it's sport climbing routes and unique geology. From Vincent Gap, the summit of Mt Baden-Powell is just another 3.8 miles on the PCT.