River Trail


Climb to the headwaters of the Middle Fork of the San Joaquin River by following the River Trail to Thousand Island Lake. Starting from shuttle bus stop #1, the River Trail and Shadow Lake Trail are combined from Agnew Meadows to a trail junction about 3 miles upstream, where the trails split and the River Trail continues to follow the San Joaquin River. At Thousand Island Lake, the River Trail joins the Pacific Crest and John Muir Trails.
Water crossings may be high during spring snow melt. This is an active bear area so you must secure your food and refuse in bear resistant food storage containers.

Download area map for trail names.
To purchase more detailed maps or guidebooks of the area, visit esiaonline.com

At a Glance

Reservations: Reserve up to 6 months in advance at Recreation.gov
Day use does not require a permit.
Rentals & Guides: Reds Meadow Pack Outfit is located near Reds Meadow Resort. 1(800) 292-7758. There is a reservable horse corral in the Agnew Meadows campground.
Fees Visitors to the Reds Meadow Valley pay a per-person transportation fee which allows use of the mandatory shuttle bus. Call Mammoth Lakes Welcome Center for more shuttle information. (760)924-5500.
Permit Info: Wilderness permits are required for overnight trips into the Ansel Adams Wilderness. Permits are issued at Inyo National Forest visitor centers.
Open Season: Road closed in winter.
Usage: Medium
Restrictions: - No campfires at Thousand Island, Garnet, Ruby, Emerald, Badger or Clark Lakes. No campfires above 10,000 ft. Campfire Restriction Maps
- No Camping within 1/4 mile of the outflow of Garnet or Thousand Island Lake.
- Bear containers are required for storage of food and trash.
- River Trail does not access the John Muir Trail until Garnet Lake or Thousand Island Lake. Shadow Creek or the High Trail - PCT are a different permit.
- Spur trail from River trail to Garnet Lake is not recommended for stock.
- Groups cannot be larger than 15 people (includes day use).
- Quota of 30 people permitted to start overnight trips each day from May 1 to November 1.
- Ansel Adams Wilderness regulations apply.
- Yosemite wilderness regulations apply if entering the National Park.
Closest Towns:  Mammoth Lakes
Water: Water from creeks, lakes and springs should be treated before drinking.
Restroom: Vault toilet at trailhead. Please Leave No Trace. Bury human waste away from water sources.
Operated By: Forest Service
Information Center: For wilderness permit information call (760) 873-2483; or for area information call the Mammoth Lakes Welcome Center (760) 924-5500

General Information


Leave Hwy 395 at Hwy 203 to the town of Mammoth Lakes. Turn right on Minaret Road and go to Mammoth Mountain Adventure Center (Main Lodge) for long term parking and to board the mandatory shuttle to the trailhead. Shuttle stop #1 is Agnew Meadows.


 Backpacker parking at Mammoth Mountain Main Lodge.



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Horse Riding & Camping

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Areas & Activities


  Latitude : 

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  Elevation : 
8,322 ft. at Agnew Meadow Trailhead - 9,839 ft. at Thousand Island Lake