Mule Bridge trailhead is the start of the North Fork Trail which follows the north fork of the Salmon River deep into the Marble Mountains Wilderness. This trail roughly parallels the PCT and get less use. The trailhead is adjacent to the Mule Bridge Horse Camp.
From Etna, take the Sawyers Bar Rd for approx. 20 miles to the Idlewild campground. Take the dirt road from Idlewild 2 miles upstream to the Mule Bridge campground. The trailhead is on the north end of the campground.