Lost Creek Trail is closed as of July 2015 due to the Lake Fire. A current Forest Order extends the closure through July of 2017.
The Lost Creek trailhead is across Highway 38 from the South Fork Campground. Beginning at the parking lot (6,320′), it crosses under the bridge. The beginning of the Lost Creek Trail follows the Santa Ana River Trail (2E03). After approximately .5 mile, the Lost Creek Trail splits from the Santa Ana River trail and heads up an old jeep road for about 1 mile before heading off (south/west) on a trail towards Grinnell Ridge Camp (no water-8,500′). From the Grinnell Ridge Camp, the trail descends into South Fork Meadows and meets with the South Fork Trail.
This trail is one of the most underused and offers solitude and good views north to Santa Ana Canyon and Sugarloaf Peak.