Highway 39 climbs deep into Southern California’s San Gabriel Mountains, starting with a steady grade that twists through rugged terrain and offers sweeping views. After passing multiple switchbacks, a Crystal Lake turnoff, and a gated parking area around mile 12, the road softens slightly, continuing along a scenic ridgeline toward the junction with Angeles Crest Highway. A final moderate push leads you to Dawson Saddle at just under 8,000 feet, a summit raced by the pros and known as one of California’s most difficult ascents.