Islip Saddle is a mountain pass in the San Gabriel Mountains of Los Angeles County, just west of Mount Islip, where State Route 2 and the northern end of State Route 39 meet. The second-highest pass on the Angeles Crest Highway after Dawson Saddle, it stands at the head of San Gabriel Canyon between Mount Williamson and Mount Islip. Named for Canadian homesteader George Islip, who lived nearby in the 1900s, it remains a major access point in the Angeles National Forest. With parking, trailheads, and Pacific Crest Trail access, it is a key hub for hikers despite seasonal road closures and the permanent closure of Route 39 beyond the saddle.