Park at the Islip Saddle day use area. Make sure you have a National Forest Adventure Pass or some other parking permit.
The trail head is across the street, at the Pacific Crest Trail marker:
The initial part of the trail has some serious switchbacks. I noticed what looks like Poodle Dog Bush (Eriodictyon parryi). Avoid this plant or you will regret it:
The trail crosses Little Jimmy Campground. It is hard to follow, and there are similar looking trails that will take you in the wrong direction. Be careful – follow your GPS or compass..
At the top are the ruins of a stone hut residence used by fire lookouts: