Where is the Dusy-Ershim Trail?
The Dusy-Ershim Trail is located in the Sierra National Forest, nestled between Courtright Reservoir and Lake Edison in Fresno County, California. This iconic high-Sierra trail spans approximately 33 miles through the John Muir Wilderness, sitting at elevations ranging from 8,200 to over 10,000 feet. It lies northeast of Fresno and is best accessed by heading toward Shaver Lake and then continuing to Courtright Reservoir.
What makes the Dusy-Ershim Trail so special?
The Dusy-Ershim Trail is widely considered one of the most challenging and scenic overland trails in the western U.S. It offers a true backcountry experience, combining rugged rock crawling with breathtaking alpine views, high-mountain meadows, granite domes, and remote lakes. It is a bucket-list trail for serious 4x4 adventurers and is part of California's famed Sierra overland routes alongside the Rubicon Trail and Fordyce Creek Trail.
How difficult is the Dusy-Ershim Trail?
Make no mistake, this is an expert-level trail. The Dusy-Ershim demands a fully capable off-road vehicle with lockers front and rear, lifted suspension, 33- to 37-inch tires minimum, and plenty of armor underneath. Expect tight squeezes between trees and rocks, long stretches of granite slabs, and boulder gardens that can easily bend parts if you're not careful. It's also long and remote, meaning you need to be mechanically self-sufficient.
The trail was originally built for short-wheelbase (and narrow) rigs (like CJs), but it is doable in a JK/JL with good spotting, some patience, and careful maneuvering in tight tree-squeeze sections.
How long does it take to run the Dusy-Ershim Trail?
Most groups complete the Dusy-Ershim Trail in 3 to 4 days, though some seasoned rigs can do it in 2 if necessary. It's best enjoyed at a slower pace, allowing time to camp at alpine lakes, fish, explore, and soak in the natural beauty. With no easy exit points, once you're in, you're committed to the full length of the trail.
What kind of vehicle is recommended for the trail?
A high-clearance 4x4 with low-range gearing is required. Jeeps, Toyotas, and purpose-built rigs with good articulation, skids, and recovery points are the standard. Here's a quick checklist:
- Lockers front & rear
- 33-inch tires minimum (35-37 preferred)
- Rock sliders and belly armor
- Spare parts and tools
- Winch (optional but highly recommended)
When is the best time to run the Dusy-Ershim Trail?
The trail is typically open from late July to mid-October, depending on snowpack and trail conditions. It's managed by the Forest Service, and the gates are closed during snow season. Always check with the Sierra National Forest or local 4x4 forums for current trail status before planning your trip.
Do you need a permit to run the trail?
Yes. Because the trail travels through the John Muir Wilderness, you'll need a free wilderness permit if you're camping overnight. These can be obtained online or at ranger stations. Group size is limited, and campfire restrictions often apply due to fire danger, so be prepared to use a camp stove.
What are the best camping spots along the trail?
There are several designated dispersed camping spots with epic views and access to water. Popular overnight spots include:
- Thompson Lake
- Ershim Lake
- East Lake
- Mirror Lake
Each offers scenic mountain backdrops, solitude, and crisp alpine air. Remember to pack out all trash and follow Leave No Trace principles.
What kind of obstacles should you expect?
The Dusy-Ershim features a wide variety of obstacles:
- Granite ledges and shelves
- Loose rock climbs
- Tight forested areas
- Water crossings (seasonal)
- Steep, rutted descents
There are no bypasses for major obstacles, and turning around is rarely an option. Body damage is possible, and breakdowns can become a serious problem if you're not prepared.
Can you bring kids or dogs on the trail?
Yes, but be smart about it. The trail is remote and demanding, with long stretches between help. Bring plenty of food, water, warm clothing, and first-aid supplies. Kids will love the lakes and campfires, but make sure they understand the environment. Dogs should be well-behaved and leashed, especially around wildlife.
What’s the cell service like on the Dusy-Ershim?
Virtually nonexistent. Do not rely on your cell phone. Bring a satellite communicator or ham radio for emergencies. Download offline maps ahead of time using Gaia, OnX Offroad, or a similar app.
Is it worth it?
If you're an experienced off-roader looking for a true backcountry challenge, the Dusy-Ershim Trail is absolutely worth every boulder, climb, and scrape. It's an unforgettable mix of technical terrain, Sierra Nevada beauty, and pure isolation that you just can't find on more crowded trails. You’ll come away exhausted, probably dinged up—and grinning ear to ear.
Final Tips:
- Travel with at least one other vehicle
- Air down your tires at the trailhead
- Watch the weather forecast—storms can move in fast
- Carry extra fuel and water
- Let someone know your itinerary
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