#3 Dusy/Ershim Trail Video: The Dusy/Ershim Trail, rated "Most Difficult" is located in the Sierra Nevada Mountains east of Fresno, California. The trail snakes along a 33-mile corridor between Dinkey Lakes and the John Muir Wilderness Areas. This trail is remote, even the drive into town is nearly one hour from either end of the trail. You’ll watch as 12 well-equipped vehicles challenge the trail, make trail repairs and fight their way over the boulders for several days before reaching the top. Our video begins at Courtright Reservoir and finishes at Kaiser Pass just above Huntington Lake. It’s the combination of Rubicon-like terrain, an abundance of small fishing lakes and remoteness of the trail that seems to attract 4-wheelers year after year. 1992. Running time approximately 55 minutes.