I hiked up to Mt. Islip at least 3 time. The view on the top at beautifull. I went solo, with my son many time. I went up from Crystal Lake called Wind Gap Trail. It is a beautifull trail; a lot of shade; not very difficult. It took two or three hours to get there. I remember, one time, I went with the boy scout. We hiked up to the junction called Windy Gap which is the PCT (Pacific Crest Trail meet ). If you trun left, you will hike up to Mt.Hawkin, Troop Peak and Baden Powell. If you turn right, you will go up to Mt. Islip. I did trun right to another mile or so. There is a building structure at the peak. The book said it was a fire lookout before. One time, a troop of boy scout hiked up there and setup camp at the that broken structure.
There are many another way to Mt. Islip. You can hike from Islip Sadle or walk up to the fire road couple mile east of Islip Sadle. I walked to the fire road many times. I passed the campground below Mt. Islip. I forget the name of the campground. My scout troop camped there before. This hike is a easy hike. Nothing is difficult. You can go many side trip. I like it trail a lot. At the peak, I would say 270 degree view because the east side is blocked about other higher peak, but the view is pretty.